VMware Interview

What is thin app.?

Vmware bought a company(Thinstall) who offer a application virtualization product.vmware rename the product as Thin apps.simmilar to the concept of Microsoft soft grid(microft application virtualization)

Thin apps allow you to virtualize your application and deliver them from server in the datacenter.

This prevent the application conflict,allow for easy software deployment,save time and money.

Can I run virtual machines created by Microsoft Virtual Server, Microsoft Virtual PC, or VMware Server on VMware ESXi? 
Yes. You can use the free VMware vCenter Converter to import virtual machines that were created using VMware Server, Microsoft Virtual Server, or Microsoft Virtual PC version 7 or higher. VMware vCenter Converter also supports conversions from sources such as physical machines and certain 3rd party disk image formats.
What is the difference between VMware ESX and VMware ESXi?
VMware ESX and VMware ESXi are both bare-metal hypervisors that install directly on the server hardware. Both provide industry-leading performance and scalability; the difference resides in the architecture and the operational management of VMware ESXi. Although neither hypervisor relies on an OS for resource management, VMware ESX relies on a Linux operating system, called the service console, to performtwo management functions: executing scripts and installing third party agents for hardware monitoring, backup or systems management. The service console has been removed from ESXi, drastically reducing the hypervisor footprint and completing the ongoing trend of migrating management functionality from the local command line interface to remote management tools. The smaller code base of ESXi represents a smaller “attack surface” and less code to patch, improving reliability and security. The functionally of the service console is replaced by remote command line interfaces and adherence to system management standards
How is VMware ESXi different than VMware vSphere?
VMware ESXi is a hypervisor that partitions a physical server into multiple virtual machines.VMware vSphere is the industry’s first cloud operating system that drastically reduces ongoing costs and increases control over delivery of service levels while still preserving the flexibility to choose between any type of OS, application and hardware architecture. VMware vSphere offers organizations high availability and centralized management functionality that span across multiple ESXi hosts such as live migration, protection against hardware failures, power management, and automatic load balancing. VMware vSphere relies on a hypervisor to partition servers. Customers can choose to deploy either VMware ESX or VMware ESXi as part of the VMware vSphere suite. All the functionality of VMware vSphere is supported on both VMware ESX and VMware ESXi. In fact, VMware vSphere supports server resource pools that contain both hypervisors.
How do I use VMware vCenter Server to manage my VMware ESXi hosts? 
VMware vCenter Server provides centralized management for ESXi hosts and their virtual machines. To manage an ESXi host with vCenter Server, you must have a vCenter Server Agent license, which is included in all editions of VMware vSphere
What is the difference between VMware ESXi and VMware Server?
VMware ESXi is an enterprise-class hypervisor that offers a bare-metal architecture for near-native performance, features like memory de-duplication to increase consolidation ratios and a cluster file system for managing VM files on shared storage. VMware ESXi and VMware ESX are the critical foundations for a dynamic and flexible virtual infrastructure.
VMware Server installs as an application on Windows or Linux, relying on the operating system for resource management. This limits the performance and scalability. VMware Server is popular for test and development activities. Virtual machines created using VMware Server can run on VMware ESXi, but they must first be converted using the free VMware Converter.
Is it possible to download a virtual appliance into an ESXi environment for evaluation? 
Yes. If you are running VMware vSphere Client 2.5 and later along with ESXi 3.5 or ESX 3.5 or later, it is possible to access a list of downloadable virtual appliances for evaluation into an ESXi environment. To access that list of virtual appliances, open your VMware vSphere client, select "Virtual Appliance" from the file menu, and then select "Import...". When you select “Import from the VMware Virtual Appliance Marketplace” and click “Next”, you will be sent to a page where you can download the appliances
How do I use VMware vCenter Server to manage my VMware ESXi hosts?
VMware vCenter Server provides centralized management for ESXi hosts and their virtual machines. To manage an ESXi host with vCenter Server, you must have a vCenter Server Agent license, which is included in all editions of VMware vSphere.

1.What is SvMotion?

   Migration of a virtual machine files and disks from one datastore to another with Zero downtime.


2. What are the use cases of SvMotion ?
  

·                         Migrating from Old storage to new storage systems or migrating to different vendor storage without downtime to VM's.

·                         Performing Scheduled activity like storage upgrades on the source Lun.  

·                         Converting VM disk type from Thick to Thin and Thin to Thick.

·                         Migrating the critical virtual machines to high performance storage arrays to improve performance of virtual Machine.

3.  What are Pre-requisites for the SvMotion to Work?

·                          ESX host in which virtual machine is running should have access to source and destination storage.

·                          ESX host should have configured with the license for svMotion

      
4. What are the Limitations of SvMotion?

·                     Virtual machines with snapshots cannot be migrated using Storage vMotion.

·                     Virtual machine with virtual compatibility RDM can be migrated with svMotion.If you convert the mapping file, a new virtual disk is created and the contents of the mapped LUN are copied to this disk.

·                      For Physical compatibility RDM, only mapping file can be relocated.

·                       Virtual Machines cannot be migrated while the VMware tools installation tools is in progress.

·                       Virtual Machine should be in powered off state if you want to migrate the VM simultaneously to different host and storage.

5. Steps involved in VMWare SvMotion ?
  

·                     svMotion copies all the files expect virtual machine disk and create the directory as same the Virtual Machine name on the destination storage.

·                     It uses Changed Block tracking to track the virtual machine disk. The change block tracking knows which region disk includes data. This data will be stored in bitmap and reside either in memory or in a file.

·                      Pre-copies Virtual machine disk and swap file will start from the source to destination datastore as the first iteration. once it is completed, It only transfers the region which were modified or written after the first iteration.

·                     ESX performs fast suspend and resume of the virtual Machine. The final changed regions will be copied to the destination  before the virtual Machine is resumed on the destination datastore.

·                     Virtual Machine will continue running on the destination datastore and source file and disk will be deleted.

·         VMWare interview questions and answers - HA (High Availability)

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What is  VMware HA?


As per VMware Definition,
VMware® High Availability (HA) provides easy to use, cost effective high availability for applications running in virtual machines. In the event of server failure, affected virtual machines are automatically restarted on other productionservers with spare capacity

What is AAM in HA?

AAM is the Legato automated availability management.  Prior to vSphere 4.1, VMware's HA is actually re engineered to work with VM's with the help of  Legato's Automated Availability Manager (AAM) software. VMware's vCenter agent (vpxa) interfaces with the VMware HA agent which acts as an intermediary to the AAM software. From vSphere 5.0, it uses an agent called “FDM”  (Fault Domain Manager).

What are pre-requites for HA to work?

1.Shared storage for the VMs running in HA cluster
2.Essentials plus, standard, Advanced, Enterprise and Enterprise Plus Licensing
3.Create VMHA enabled Cluster
4.Management network redundancy to avoid frequent isolation response in case of temporary network issues (preferred not a requirement)

What is maximum number of primary HA hosts in vSphere 4.1?

Maximum number of primary HA host is 5. VMware HA cluster chooses the first 5 hosts that joins the cluster as primary nodes and all others hosts are automatically selected as secondary nodes.

How to see the list of Primary nodes in HA cluster?

View the log file named "aam_config_util_listnodes.log" under /var/log/vmware/aam using the below command

cat /var/log/vmware/aam/aam_config_util_listnodes.log

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What is the command to restart /Start/Stop HA agent in the ESX host?

service vmware-aam restart

service vmware-aam stop

service vmware-aam start

Where to located HA related logs in case of troubleshooting?

/Var/log/vmware/aam

What the basic troubleshooting steps in case of HA agent install failed on hosts in HA cluster?

Below steps are are taken from my blog posts Troubleshooting HA

1. Check for some network issues

2. Check the DNS is configured properly

3. Check the vmware HA agent status in ESX host by using below commands

  service vmware-aam status

4. Check the networks are properly configured  and named exactly as other hosts in the cluster. otherwise, you will get the below errors while installing or reconfiguring HA agent.

5. Check HA related ports are open in firewall to allow for the communication
    
     Incoming port: TCP/UDP 8042-8045
     Outgoing port: TCP/UDP 2050-2250

6. First try to restart /stop/start the vmware HA agent on the affected host using the below commands. In addition ucan also try to restart vpxa and management agent in the Host.

        service vmware-aam restart

        service vmware-aam stop

        service vmware-aam start

7. Right Click the affected host and click on "Reconfigure for VMWare HA" to re-install the HA agent that particular host.

8. Remove the affected host from the cluster. Removing ESX host from the cluster will not be allowed untill that host is put into maintenance mode.

9.Alternative solution for 3 step is, Goto cluster settings and uncheck the vmware HA in to turnoff the HA in that cluster and re-enable the vmware HA to get the agent installed.

10. For further troubleshooting , review the HA logs under /Var/log/vmware/aam directory.


What is the maximum number of hosts per HA cluster?

Maximum number of hosts in the HA cluster is 32


What is Host Isolation?

VMware HA has a mechanism to detect a host is isolated from rest of hosts in the cluster. When the ESX host loses its ability to exchange heartbeat via management network between the other hosts in the HA cluster, that ESX host will be considered as a Isolated.

How Host Isolation is detected?

In HA cluster, ESX hosts uses heartbeats to communicate among other hosts in the cluster.By default, Heartbeat will be sent every 1 second.

If a ESX host in the cluster didn't received heartbeat for for 13 seconds from any other hosts in the cluster, The host considered it as isolated and host will ping the configured isolation address(default gateway by default). If the ping fails, VMware HA will execute the Host isolation response


What are the different types isolation response available in HA?

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Power off –  All the VMs are powered off , when the HA detects that the network isolation occurs

Shut down – All VMs running on that host are shut down with the help of VMware Tools, when the HA detects that the network isolation occurs.If the shutdown via VMWare tools not happened within 5 minutes, VM's power off operation will be executed. This behavior can be changed with the help of HA advanced options. Please refer my Post on HA Advanced configuration


Leave powered on –  The VM's state remain powered on or remain unchanged, when the HA detects that the network isolation occurs.

How to add additional isolation address for redundancy?

By default, VMWare HA use to ping default gateway as the isolation address if it stops receiving heartbeat.We can add an additional values in case if we are using redundant service  console both belongs to different subnet.Let's say we can add the default gateway of SC1 as first value and gateway of SC2 as the additional one using the below value

1. Right Click your HA cluster

2. Goto to advanced options of HA

3. Add the line "das.isolationaddress1 = 192.168.0.1"

4. Add the line "das.isolationaddress2 = 192.168.1.1" as the additional isolation address

To know more about the Advanced HA Options

What is HA Admission control?

As per "VMware Availability Guide",

VCenter Server uses admission control to ensure that sufficient resources are available in a cluster to provide failover protection and to ensure that virtual machine resource reservations are respected.

What are the 2 types of settings available for admission control?

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Enable: Do not power on VMs that violate availability constraints

Disable: Power on VMs that violate availability constraints


What are the different types of Admission control policy available with VMware HA?

There are 3 different types of Admission control policy available.

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Host failures cluster  tolerates
Percentage of cluster resources reserved as fail over spare capacity
Specify a fail over host

How the Host Failures cluster tolerates admission control policy works?

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Select the maximum number of host failures that you can afford for or to guarantee fail over. Prior vSphere 4.1, Minimum is 1 and the maximum is 4.

In the Host Failures cluster tolerates admission control policy , we can define the specific number of hosts  that can fail  in the cluster and also it ensures that the sufficient resources remain to fail over all the virtual machines from that failed hosts to the other hosts in cluster. VMware High Availability(HA) uses a mechanism called slots to calculate both the available and required resources in the cluster for a failing over virtual machines from a failed host  to other hosts in the cluster.

What is SLOT?

As per VMWare's Definition,

"A slot is a logical representation of the memory and CPU resources that satisfy the requirements for any powered-on virtual machine in the cluster."

If you have configured reservations at VM level, It influence the HA slot calculation. Highest memory reservation and highest CPU reservation of the VM in your cluster determines the slot size for the cluster.

How the HA Slots are Calculated?

I have written a post about how the HA slots are calculated.

How to Check the HA Slot information from vSphere Client?

Click on Cluster Summary Tab and Click on "Advanced Runtime Info" to see the the detailed HA slots information.

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What is use of Host Monitoring  status in HA cluster?

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Let's take an example, you are performing network maintenance activity on your switches which connects your one of thESX host in HA cluster.

what will happen if the switch connected to the ESX host in HA cluster is down?

It will not receive heartbeat and also ping to the isolation address also failed. so, host will think itself as isolated and HA will initiate the reboot of virtual machines on the host to other hosts in the cluster. Why do you need this unwanted situation while performing scheduled maintenance window.

To avoid the above situation when performing scheduled activity which may cause ESX host to isolate, remove the check box in " Enable Host Monitoring" until you are done with the network maintenance activity.


How to Manually define the HA Slot size?

By default, HA slot size is determined by the Virtual machine Highest CPU and memory reservation. If no reservation is specified at the VM level, default slot size of 256 MHZ for CPU and 0 MB + memory overhead for RAM will be taken as slot size. We can control the HA slot size manually by using the following values.

There are 4 options we can configure at HA advanced options related to slot size

das.slotMemInMB - Maximum Bound  value for HA memory slot size
das.slotCpuInMHz - Maximum Bound value for HA CPU slot Size
das.vmMemoryMinMB -  Minimum Bound  value for HA memory slot size
das.vmCpuMinMHz -  Minimum Bound  value for HA CPU slot size

For More HA related Advanced options, Please refer my blog post


How the "Percentage of cluster resources reserved as failover spare capacity" admission control policy works?

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In the Percentage of cluster resources reserved as failover spare capacity admission control policy, We can define the specific percentage of total cluster resources are reserved for failover.In contrast to the "Host Failures cluster tolerates admission control policy", It will not use slots. Instead This policy calculates the in the way below


1.It calculates the Total resource requirement for all Powered-on Virtual Machines in the cluster  and also calculates the total resource available in host for virtual machines.
2.It calculates the current CPU and Memory Failover capacity for the capacity.
3.If the current CPU and Memory Failover capacity for the cluster < configured failover capacity (ex 25 %)
4.Admission control will not allow to power on the virtual machine which violates the availability constraints.


How the "Specify a failover host" admission control policy works?

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In the Specify a failover host" admission control policy, We can define a specific host as a dedicated failover host. Whenisolation response is detected, HA attempts to restart the virtual machines on the specified failover host.In this Approach, dedicated failover hist will be sitting idle without actively involving or not participating in DRS load balancing.DRS will not migrate or power on placement of virtual machines on the defined failover host.


What is VM Monitoring status?

HA will usually monitors ESX hosts and reboot the virtual machine in the failed hosts in the other host in the cluster in case of host isolation but i need the HA to monitors for Virtual machine failures also. here the feature called VM monitoring status as part of HA settings.VM monitoring restarts the virtual machine if the vmware tools heartbeat didn't received with the specified time using Monitoring sensitivity.

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If you are looking for more VMware interview questions Please click  Interview Questions.

Thanks For Reading!!! All the Best...

·         VMWare interview questions and answers -Networking

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What is Service Console?

The service console is developed based up on Redhat Linux Operating system, it is used to manage the VMKernel

What are the basic commands to troubleshoot  connectivity between vSphere Client /vCenter to ESX server?

service mgmt-vmware restart  (restarts host agent(vmware-hostd) on vmware esx server)

service vmware-vpxa restrat (restarts Vcenter agent service)

service network restart (restarts management networks on ESX)


What is vCenter Agent?

VC agent is an agent installed on ESX server which enables communication between VC and ESX server. This Agent will be installed on ESX/ESXi will be done when you try to add the ESx host in Vcenter.


What is the command used to restart SSH, NTP & Vmware Web access?

Service sshd restart

Service ntpd restrat

Service vmware-webaccess restart

What are the types of Ports groups in ESX/ESXi?

There are 3 types of port groups in ESX

1.Service console port group
2.VMkernel Port group
3. Virtual machine port group

There are only 2 types of port group in ESXi

1. Vmkernel Port group
2.Virtual Machine Port group

What is VMKernel ?

VMWare Kernel is a Proprietary kernel  of vmwareand is not based on any of the flavors of Linux operating systems, .VMkernel requires an operating system to boot and manage the kernel. A service console is being provided whenVMWare kernel is booted. Only service console is based up on Redhat Linux OS not VMkernel.

What is the use of Service Console port ?

Service console port group required to manage the ESX server and it acts as the management network for the ESX.Vcenter/Vsphere Client uses the service console IP's to communicate with the ESX server.

What is the use of VMKernel Port ?

Vmkernel port is used by ESX/ESXi for vmotion, ISCSI & NFS communications. ESXi uses Vmkernel as the management network  since it don't have service console built with it.

What is the use of Virtual Machine Port Group?

Virtual Machine port group is used by Virtual machine communication.

How Virtual Machine communicates to another servers in Network ?

All the Virtual Machines which are configured in VM Port Group are able to connect to the other machines on the network. So this port group enables communication between vSwitch and Physical Switch by the use of uplink (Physical NIC) associated with the port group.

What is the default number of ports configured with the Virtual Switch?

When the time of Virtual switch created, Vswitch is created with 56 ports by default. We can extend the no of ports by editing the vswitch properties.



What are the different types of Partitions in ESX server?

/ -root
Swap
/var
/Var/core
/opt
/home
/tmp


What are the security options available for ESX vswitch?

Promiscuous Mode - Reject
MAC Address changes - Accept
Forged Transmits - Accept

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What is Promiscuous Mode ?

If the promiscuous mode set to Accept, all the communication is visible to all the virtual machines, in other words all the packets are sent to all the ports on vSwitch. It can be useful when you are running virtual machines with network sniffers to capture packet in that network.



What is MAC Address changes?

All the virtual machines nics are provide with the MAC address at the time of creation and it is stored in .VMX file. If the packet  doesn't match with the MAC address as same as in the .VMX  file , it does not allow incoming traffic to the VM by setting this option as reject.

If it is set as Accept,ESX accepts requests to change the effective MAC address to other than the MAC address save din the .VMX file.



What is Forged Transmits ?

Which is same as the Mac Address changes setting but it worked for the outgoing traffic but the MAC address changes setting is for incoming traffic.

What is a VLAN ?

A VLAN is the Virtual LAN which is used to broke down the Broadcast traffic into many logical groups. Basically, one physical switch comprise of one broadcast domain. VLAN used to separate the one broadcast domain into many small pieces to separate the networks within the broadcast domain.


What are the types of VLAN tagging in Vsphere?

There are 3 types of VLAN tagging available in Vsphere.

1.Virtual Switch Tagging (VST)
2.External Switch Tagging (EST)
3.Virtual Guest Tagging (VGT)

What is VST , EST & VGT?

Please refer my blog post on VST , EST & VGT .


What are the Traffic Shaping policies available in the Vswitch?

Traffic shaping policies are disabled by default. There are 3 different traffic shaping policy setting

Average Bandwidth
Peak Bandwidth
Burst Size

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Average Bandwidth is defined in KBPS
Peak bandwidth is defined in KBPS
Burst Size is defined in Kilobytes

What are the Load balancing policies available in vswitch?

Route based on the originating virtual switch port ID
Route based on source MAC hash
Route based on IP hash

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Route based on the originating virtual switch port ID - Chooses an uplink based on the virtual port where the traffic entered the virtual switch.  The traffic will be always send with that same uplink until that particular uplink is failed and failed over to another NIC.

Route based on source MAC hash - Choose an uplink based on a hash of the source Ethernet MAC address.The traffic will be always send with that same uplink until that particular uplink is failed and failed over to another NIC.

Route based on IP hash - Choose an uplink based on a hash of the source and destination IP addresses of each packet.



What are the  types for Network Failover Detection settings?

Link Status only
Beacon Probing

Link Status only - Relies solely on the link status provided by the network adapter. This detects failures, such as cable pulls and physical switch power failures, but it cannot detect configuration errors, such as a physical switch port being blocked by spanning tree or misconfigured to the wrong VLAN or cable pulls on the other side of a physical switch.

Beacon Probing -  Sends out and listens for beacon probes — Ethernet broadcast frames sent by physical adapters to detect upstream network connection failures — on all physical Ethernet adapters in the team. In addition to link status, to determine link failure. This detects many of the failures which are not detected by Link Status.



What is the command to  check the IP address along with the detailed network cards assigned to the esx server?


Ifconfig -a

Output appears like this
========================================================================

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:9365 errors:0 dropped:0 overruns:0 frame:0
          TX packets:9365 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:8127714 (7.7 MiB)  TX bytes:8127714 (7.7 MiB)

vmnic0    Link encap:Ethernet  HWaddr 00:0C:29:85:0D:76
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:100772 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5103 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:35475848 (33.8 MiB)  TX bytes:402120 (392.6 KiB)
          Interrupt:145

vmnic1    Link encap:Ethernet  HWaddr 00:0C:29:85:0D:80
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:105895 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:35894203 (34.2 MiB)  TX bytes:0 (0.0 b)
          Interrupt:129

vmnic2    Link encap:Ethernet  HWaddr 00:0C:29:85:0D:8A
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:105908 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:35895750 (34.2 MiB)  TX bytes:0 (0.0 b)
          Interrupt:137

vmnic3    Link encap:Ethernet  HWaddr 00:0C:29:85:0D:94
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:105690 errors:0 dropped:0 overruns:0 frame:0
          TX packets:228 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:35883279 (34.2 MiB)  TX bytes:13680 (13.3 KiB)
          Interrupt:145

vswif0    Link encap:Ethernet  HWaddr 00:50:56:4D:69:D1
          inet addr:192.168.0.75  Bcast:192.168.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:14893 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2575 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:966513 (943.8 KiB)  TX bytes:230028 (224.6 KiB)

vswif1    Link encap:Ethernet  HWaddr 00:50:56:4F:45:B1
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:11042 errors:0 dropped:0 overruns:0 frame:0
          TX packets:30 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:717158 (700.3 KiB)  TX bytes:1260 (1.2 KiB)

=========================================================================

You can use "ip addr" command also to view the ip information

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[root@ESXTEST1 etc]# ip addr
1: lo: mtu 16436 qdisc noqueue
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
2: vmnic0: mtu 1500 qdisc noop qlen 1000
    link/ether 00:0c:29:85:0d:76 brd ff:ff:ff:ff:ff:ff
3: vmnic1: mtu 1500 qdisc noop qlen 1000
    link/ether 00:0c:29:85:0d:80 brd ff:ff:ff:ff:ff:ff
4: vmnic2: mtu 1500 qdisc noop qlen 1000
    link/ether 00:0c:29:85:0d:8a brd ff:ff:ff:ff:ff:ff
5: vmnic3: mtu 1500 qdisc noop qlen 1000
    link/ether 00:0c:29:85:0d:94 brd ff:ff:ff:ff:ff:ff
6: vswif0: mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:50:56:4d:69:d1 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.75/24 brd 192.168.0.255 scope global vswif0
7: vswif1: mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:50:56:4f:45:b1 brd ff:ff:ff:ff:ff:ff
9: vswif2: mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:50:56:43:92:be brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.96/24 brd 192.168.0.255 scope global vswif2

=========================================================================


what is the command to check the ESX vswitch details, port group and its ip address?

Esxcfg-vswitch -l
Outuput will appear like this:
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[root@ESXTEST1 ~]# esxcfg-vswitch -l
Switch Name    Num Ports   Used Ports  Configured Ports  MTU     Uplinks
vSwitch0       32          4           32                1500    vmnic0

  PortGroup Name      VLAN ID  Used Ports  Uplinks
  Service Console     0        1           vmnic0
  VMkernel            0        1           vmnic0

Switch Name    Num Ports   Used Ports  Configured Ports  MTU     Uplinks
vSwitch1       64          3           64                1500    vmnic2,vmnic1

  PortGroup Name      VLAN ID  Used Ports  Uplinks
  VM-10.0.0 subnet    0        0           vmnic2,vmnic1
  VM-192.168.0 subnet 0        0           vmnic2,vmnic1

Switch Name    Num Ports   Used Ports  Configured Ports  MTU     Uplinks
vSwitch2       64          4           64                1500    vmnic3

  PortGroup Name      VLAN ID  Used Ports  Uplinks
  Service Console 2   0        1           vmnic3
  Vmotion             0        1           vmnic3
=========================================================================
From the above output,
we come to know that we have 3 virtual switches named vSwitch0,vSwitch1 and vSwitch2.
4 uplinks (physical nics in our esx server) Vmnic0,vmnic1,vmnic2,vmnic3.
vswitch0 constains 2 port group (Service Console & VMKernel), vSwitch1 contains 2 virtual machine port group (VM-10.0.0 subnet & VM-192.168.0 subnet) and Vswitch2 contains 2 port group (Service Console 2 & Vmotion) port group.

What is command to get the information about Service console ports and its IP address assigned to it?

esxcfg-vswif -l

Output will appear like this:

=========================================================================
[root@ESXTEST1 ~]# esxcfg-vswif -l
Name     Port Group/DVPort   IP Family IP Address                              Netmask                                 Broadcast        Enabled   TYPE
vswif0   Service Console     IPv4      192.168.0.75                            255.255.255.0                           192.168.0.255    true      STATIC
vswif1   Service Console 2   IPv4      192.168.0.78                            255.255.255.0                           192.168.0.255    false     STATIC
=========================================================================

what is the command to get the information about vmkernel ports and its ip address?
esxcfg-vmknic -l

Output will appear like this:

=========================================================================
[root@ESXTEST1 ~]# esxcfg-vmknic -l
Interface  Port Group/DVPort   IP Family IP Address                              Netmask         Broadcast       MAC Address       MTU     TSO MSS   Enabled Type
vmk0       VMkernel            IPv4      192.168.0.110                           255.255.255.0   192.168.0.255   00:50:56:78:7e:73 1500    65535     true    STATIC
vmk1       Vmotion             IPv4      192.168.0.77                            255.255.255.0   192.168.0.255   00:50:56:76:42:df 1500    65535     true    S
=========================================================================


what is the command to get the information about physical nics installed on ESX server?
esxcfg-vmknic -l

Output will appear like this:
=========================================================================
[root@ESXTEST1 sbin]# esxcfg-nics -l
Name    PCI      Driver      Link Speed     Duplex MAC Address       MTU    Description
vmnic0  02:00.00 e1000       Up   1000Mbps  Full   00:0c:29:85:0d:76 1500   Intel Corporation 82545EM Gigabit Ethernet Controller (Copper)
vmnic1  02:02.00 e1000       Up   1000Mbps  Full   00:0c:29:85:0d:80 1500   Intel Corporation 82545EM Gigabit Ethernet Controller (Copper)
vmnic2  02:03.00 e1000       Up   1000Mbps  Full   00:0c:29:85:0d:8a 1500   Intel Corporation 82545EM Gigabit Ethernet Controller (Copper)
vmnic3  02:04.00 e1000       Up   1000Mbps  Full   00:0c:29:85:0d:94 1500   Intel Corporation 82545EM Gigabit Ethernet Controller (Copper)
========================================================================

What is command to add the new virtual switch named (vswitch3) to our ESX server?


[root@ESXTEST1 sbin]# esxcfg-vswitch -a vswitch3

Now vswitch3 is created without any port group.

======================================================================

Switch Name    Num Ports   Used Ports  Configured Ports  MTU     Uplinks
vswitch3       64          1           64                1500

  PortGroup Name      VLAN ID  Used Ports  Uplinks
========================================================================

What is command to add the new port group  named (mgmt)to vswitch (vswitch 3) ?


[root@ESXTEST1 sbin]# esxcfg-vswitch -A mgmt vswitch3

now port group "mgmt" is added.

=========================================================================
Switch Name    Num Ports   Used Ports  Configured Ports  MTU     Uplinks
vswitch3       64          1           64                1500

  PortGroup Name      VLAN ID  Used Ports  Uplinks
  mgmt                0        0
=========================================================================



How to add the service console port (vswif2) to our newly created port group "mgmt" with the ip addr 192.168.0.79 ?


[root@ESXTEST1 sbin]# esxcfg-vswif -a vswif2 -i 192.168.0.79 -n 255.255.255.0 -p "mgmt"

where i is the ip address, n is subnet mask p is to mentione the port group name
=========================================================================
vswif2   mgmt                IPv4      192.168.0.79                            255.255.255.0                           192.168.0.255    true      STATIC
=========================================================================

 How to add the vmkernal port (vmk2)  to our newly created port group "mgmt" with the ip addr 192.168.0.83?


[root@ESXTEST1 sbin]# esxcfg-vmknic -a  -i 192.168.0.83 -n 255.255.255.0 -p "mgmt"

=========================================================================
vmk2       mgmt                IPv4      192.168.0.83               255.255.255.0   192.168.0.255   00:50:56:7b:bd:36 1500    65535     true    STATIC
=========================================================================

How to change the ip addresss of the existing service console "vswif2"?
nano /etc/sysconfig/network-scripts/ifcfg-vswif2. 

Edit the file with your new id address " 192.168.0.255" then save and exit.
======================================================
DEVICE=vswif2
HOTPLUG=yes
MACADDR=00:50:56:43:92:be
ONBOOT=yes
PORTGROUP=mgmt
BOOTPROTO=static
BROADCAST=192.168.0.255
DHCPV6C=no
IPADDR=192.168.0.96
IPV6INIT=no
IPV6_AUTOCONF=no
NETMASK=255.255.255.0
======================================================
restart the network service for ip change to take effect:

[root@ESXTEST1 sysconfig]# service network restart
Shutting down interface vswif0:                            [  OK  ]
Shutting down interface vswif2:                            [  OK  ]
Shutting down loopback interface:                          [  OK  ]
Bringing up loopback interface:                            [  OK  ]
Bringing up interface vswif0:                              [  OK  ]

Another way is to connect to the console of the ESX server and at the shell prompt type in :esxcfg-vswif -d vswif2

This will delete the existing vswif0 and it will give the message about "nothing to flush".

then type the below command

esxcfg-vswif -a vswif2 -p mgmt -i 192.168.0.97 -n 255.255.255.0
=========================================================================
[root@ESXTEST1 etc]# esxcfg-vswif -d vswif2
Nothing to flush.
[root@ESXTEST1 etc]# esxcfg-vswif -a vswif2 -p mgmt -i 192.168.0.97 -n 255.255.255.0
[2011-09-17 19:35:46 'Vnic' warning] Generated New MAC address, 00:50:56:43:92:be for vswif2
Nothing to flush.
=========================================================================

How to change  the  ESX host name and default gateway?


edit the below file:


nano  /etc/sysconfig/network
======================================
NETWORKING=yes
HOSTNAME=ESXTEST1.lab.com
GATEWAY=192.168.0.20
GATEWAYDEV=vswif0
IPV6_AUTOCONF=no
NETWORKING_IPV6=no
======================================
restart the network service for ip change to take effect:

[root@ESXTEST1 sysconfig]# service network restart


 How to edit the  ESX host file ?


nano /etc/hosts


Edit the file to make entry to your host file.
==========================================
127.0.0.1       localhost
::1             localhost
192.168.0.75    ESXTEST1.lab.com ESXTEST1
==========================================

How to edit the DNS entry of your ESX server?


nano /etc/resolv.conf

Edit the file to make changes or to make new entry of dns for your ESX server
========================
nameserver 192.168.0.20
search lab.com
=======================

 what is the command to query the firewall ports ?


esxcfg-firewall - q

How  to open the port in firewall  (port no 8877, tcp, incoming , name: test3 ?

esxcfg-firewall -o 8877,tcp,in,test3

VMWare Performance CPU & Memory Metrics

Most of the times, I find difficulty to understand the Performance metrics of Virtual Machine displayed in the vCenter at my initial stages of learning. But Now I believe that got little bit understanding. This post is for to help  the VMware beginners to understand Virtual Machine Performance metrics. Understanding the Performance metrics of virtual Machine is extremely useful  to troubleshoot the virtual Machine Performance issues.

There are 2 Places Where we can check the Performance metrics of Virtual Machine in vCenter Server

1. Summary Tab of Virtual Machine
2.Resource Allocation Tab of Virtual Machine

Let's Take a detailed look of each virtual machine performance metrics.

Below Snapshot is the general overview about the Virtual Machine and its allocated resources. My virtual Machine has allocated with 1vCPU and 4096 MB (4 GB) of Memory 

 Memory Overhead  (164.47 MB)
ESX Hosts requires some amount of Memory as Memory Overhead to run this virtual Machine workload like Virtual Machine frame buffer and Mapping table etc.In our case, ESX requires 164.47 MB memory overhead to run this virtual machine in addition to the Configured memory of 4 GB. 

 

Consumed Host CPU   26 MHZ

Consumed Host CPU is the amount of ESX server's CPU consumed by the virtual Machine

Consumed Host Memory   2057.00 MB

  
Consumed Memory is the amount of ESX server's physical memory consumed by the virtual

machine and this value also includes the Memory overhead for this virtual machine.Consumed Host Memory displays the highest amount of memory used by that VM in other words touched memory. Generally, Windows Operating system will touch almost all the memory assigned to that virtual machine during boot time.

Active Guest Memory  204.00 MB

Active Guest Memory is the amount of memory that VMkernel believes that it has been actively used by virtual machine.

Provisioned Storage , Non-Shared Storage & Used Storage

Please Refer my Blog post on Provisioned Storage , Non-Shared Storage & Used Storage

Resource Allocation Tab of Virtual Machine - Memory

 

Host Memory

Consumed  (2.01 GB)

Consumed is the amount of ESX server machine memory currently allocated to this virtual Machine. Out of 4 GB of Configured Memory, 2.01 GB is being consumed by our virtual Machine 

Overhead Consumption  (109.00 MB)

Overhead Consumption is the amount of memory consumed for the Visualization overhead to run this particular virtual machine

Guest Memory

Private Guest Memory (1.09 GB)

Private memory is the amount of memory that is physically backed by the Host.Private memory is calculated using the below formula

Private memory = VM Allocated Memory  – Unaccessed Memory – Shared Memory 

Private Memory = 4 GB - 84.00 MB - 2.01 GB

Shared Guest Memory  (2.01 GB)

Shared Guest Memory is the amount of memory which is shared through the TPS (Transparent Page sharing) one of the memory management Technique of ESX server.This value also includes the memory shared with other Virtual Machines and  shared within the Virtual Machine.

Swapped Memory  (0 MB)

Swapped Memory is the amount of guest Physical memory swapped out to the Virtual Machine's swap device by the ESX kernel (VMkernel). This value refers to the VMkernel swapping not the Guest operating system swapping activity. 

Ballooned  (0 MB)

The Balloon memory is the amount of guest physical memory that is currently reclaimed through the balloon driver (vmmemctl). This is carried out by one of the Memory management technique of ESX server named Memory Ballooning. 

Unaccessed  (84.00 MB)

Unaccessed memory is the  current amount of memory not being accessed by the Virtual machine (free memory for the guest)

Active (122.0 MB)

Active Guest Memory is the amount of memory that it has been actively used by the virtual machine.

Resource Settings 

Reservation  (0 MB)

Reservation is the minimum amount of memory guaranteed to the virtual Machine. At any cost, That particular virtual machine always assigned the reserved memory. We dont have memory reservation configured for our virtual machine so, the value displayed above is 0 MB.

Limit  (unlimited)

Limit is just opposite to the Reservation. Limit is the upper cap of the virtual machine memory. If the virtual machine is configured with 4 GB of memory but memory limit is set as 3 GB. Virtual machine cannot use memory more than 3 GB. This is the upper cap limit of memory. For our Virtual machine, we didn't configured memory limit so it is displayed as unlimited.

To configure Memory reservation and Limit, Go to Virtual Machine -> Edit Settings -> Resources Tab -> Memory

Move the slider towards right side to configure reservation and Un-check the unlimited to specify the memory limit.

Configured  (4 GB)

Configured  memory is the total amount of memory configured for the virtual machine.

Shares  (Normal)

Shares determine the relative weight of virtual machine among its siblings i.e other virtual Machines in same ESX host or Resource pools.If a virtual Machine has more memory shares as compared to the other virtual machines in same ESX host or in resource pool, it is entitled to receive more resources, when the virtual machines are competing for memory resources in case of contention.

You can see the share value of each virtual Machine by going to resource allocation tab of cluster or Resource Pool

There are 3  different types of share value

1.High

2.Norma

3. Low

The ratio between is Share value of  High:Normal:Low is 4:2:1. You can use the same method which used to configure Reservation and Limit to change the share value of virtual machine too.

Worst Case allocation  (4.17 GB)

Worst case allocation is the amount of memory that virtual machine can allocate When all the virtual Machines in the ESX or Cluster consumes its full amount of its configured or allocated resources. This is the Value of memory the VM will get in this scenario.

Overhead reservation  (176 MB)

This is the amount of memory reserved for the Virtualization overhead for this virtual Machine.

How to reset a forgotten ESX server root password

This post describes the steps to reset a forgotten or lost ESX password.Connect your ESX host via remote console (ILO, DRAC,etc.) or access the ESX server directly from the data center server room.

1. Boot the ESX server and hit "a" when ESX boots with grub menu to edit kernel arguments.

2.Type the command "single"  and hit enter

3.ESX will boot up and  the below prompt will come up after the boot up. Type "passwd" and hit enter.

4. Enter the new password for root and re-type the password for the confirmation

You will get the message "passwd: all authentication tokens updated successfully". Reboot the ESX host to login with the newly assigned password.

Thanks for Reading!!!

Configuring IP Address for ESXi Host

This Post describes the step by step procedure to configure IP address for ESXi host. Unlike ESX host, ESXi doesn't have a service console but it has DCUI (Direct console User interface) to perform basic operation.We look into the steps to configure IP address for ESXi host Via DCUI.

Please refer My post for the steps to install ESXi 5 Host

Connect to the console of your ESXi host and Press F2

Login with the root credentials

Select "Configure Management Network" and hit enter

Select the Network Adapter for your ESXi host management network and Hit enter

Select the NIC Card by [X} against the NIC and hit Enter for OK.

Select the VLAN for your management network. I have no VLAN configured in my environment. So leave it to not set

Select the IP configuration to change the IP address from DHCP assigned to static IP address and Hit Enter

Enter the IP address, Subnet mask and Default gateway for the ESXi server management network and Hit Enter to OK.

Select the DNS configuration and hit Enter to Chnage the DNS infomration

Provide the Primary and secondary DNS server. Enter the Host name for your ESXi host and Hit Enter to OK.

Press ESC to come back from the network configuration screen and Type "Y" to apply changes and restart management network for the changes to take effect.

Note Down the below Screenshot. Now, We have our ESXi host assigned with the static IP address and Host name.

Install ESX/ESXi Server on VMware Workstation - Part 1

This Post describes the step by step procedure to install ESXi 5 server on VMWare Workstation. Basically for Lab purposes, we cannot afford a dedicated server or hardware for running ESX/ESXi server. So The alternative is to start playing with ESX server running it in your Laptop or desktop. This installation of ESXi 5 is tested on my Laptop with the below configuration

Dell Latitude 

Core i5 processor and 3 GB RAM.

Windows XP Professional OS

VMware Workstation 8.0.0 build-471780

There Are few options to test your hardware/Server/laptop is capable of running ESX Server either directly or running as a virtual machine inside VMware Workstation.

1. VMware CPU Identification Utility

   Refer my blog post on  how to test CPU Identification Utility on VMware Workstation

2. Intel  Processor Identification Utility

Refer my blog post on how to run Intel  Processor Identification Utility to test CPU for ESX Install as Virtual Machine.

Open the VMware Workstation and goto  File -> New ->Virtual Machine.

Select the Custom radio button and click on Next

Select Hardware Compatibility as "Workstation 8.0" and it displays the compatible products and Limitations of this hardware compatibility. We are capable of running ESXi 5.0 with Workstation 8.0.

 

Click on Browse to attach the ESXi 5.0 ISO image to attach with this installation and click on Next.

 

 

Provide the Name for the virtual machine and location on the local disk to store the virtual machine files like vmx, vmdk, etc.  

 

Accept the default Processor configuration as below and click on next.

 

Minimum memory requirement to power on the ESX/ESXi server 2048 MB (2 GB). So make sure you have selected memory more than 2 GB.

 

Select the Network connection type as per your convenience and click on Next. I have selected "Bridge Networking" to give the guest OS direct access to an external Ethernet network.

 

Accept the default controller type. LSI Logic is the recommended and click on Next.

 

Select " Create a new Virtual disk" for ESXi server installation.

Select the disk type. SCSI is the recommended type and click on Next.

 

Specify the Disk capacity and select store virtual disk as a single file.

 

Specify the Disk file. By default it will be stored with the virtual machine location. If you want to specify the different location for virtual disk file, we can define it by clicking on Browse.

 

Virtual Machine is ready to create and click on customize hardware to remove unwanted devices before proceed with the ESXi installation.

Remove unnecessary devices like Floppy, USB controller and click on Close.

Virtual Machine is created and Next step is to proceed with the ESXi installation.

Please refer my blog post Install ESX/ESXi Server on VMware Workstation - Part 2 for the ESXi installation step by step procedure.

Install ESX/ESXi Server on VMware Workstation - Part 2

This post explains the step by step procedure for how to install ESXi 5 on VMware Workstation. If you want to know how to create ESXi virtual machine in VMware Workstation, Please refer my Blog post 

Install ESX/ESXi Server on VMware Workstation - Part 1

As mentioned in the Part 1 , We have created VM and attached ESXi installation ISO. Now power on the virtual machine to boot from the ISO. Hit enter to Boot from ESXi 5.0 Installer.

 

Installer is Loading Files

 

On the Welcome Screen, Hit Enter to continue With the Installation

 

Hit F11 to Accept and continue the License agreement

 

Installer is Scanning for available devices

 

Select the disk fort he ESXi install . We have only one disk. Hit enter to continue.

 

Select US Default as the keyboard layout  and Enter to continue

 

 

It shows the Warnings that Hardware Virtualization is not a feature of the CPU. No Problem. Enter to continue

 

Hit F11 to start the installation

 

It takes Few minutes to complete the installation

Installation completed successfully and hit Enter to reboot

 

Now, ESXi booted and Ready for the Configuration.

VMWare vCenter Converter Standalone - Installation

This post describes about the steps to install vCenter Converter Standalone installation.

VMware vCenter Converter Standalone is a VMware's product to convert physical machines, virtual machines and also some third party backup images to VMware virtual machines.It's a free product from VMware and also an alternative for the small enterprises who cannot afford for VMware vCenter converter license. Let's look at the step by step installation steps for VMware vCenter Converter standalone.


Download the vCenter Converter Standalone. from the VMware website.

Double click the Converter setup.exe and select "English" as the language for this installation.

Click on the Next to start the Converter installation

Accept the End-User Patet Agreement and click on Next

Accept the End-User License Agreement by selecting " I accept the terms in the License Agreement" and click on Next to continue.

Select the Installation Location by click on Change. I am using the default installation location.

Select the component to install as part of this installation and click Next.

Review the post settings and if any port needs to change, enter the port number and click on Next.

The install will start and takes few seconds to complete.

What is  VMware HA?


As per VMware Definition,
VMware® High Availability (HA) provides easy to use, cost effective high availability for applications running in virtual machines. In the event of server failure, affected virtual machines are automatically restarted on other productionservers with spare capacity

What is AAM in HA?

AAM is the Legato automated availability management.  Prior to vSphere 4.1, VMware's HA is actually re engineered to work with VM's with the help of  Legato's Automated Availability Manager (AAM) software. VMware's vCenter agent (vpxa) interfaces with the VMware HA agent which acts as an intermediary to the AAM software. From vSphere 5.0, it uses an agent called “FDM”  (Fault Domain Manager).

What are pre-requites for HA to work?

1.Shared storage for the VMs running in HA cluster
2.Essentials plus, standard, Advanced, Enterprise and Enterprise Plus Licensing
3.Create VMHA enabled Cluster
4.Management network redundancy to avoid frequent isolation response in case of temporary network issues (preferred not a requirement)

What is maximum number of primary HA hosts in vSphere 4.1?

Maximum number of primary HA host is 5. VMware HA cluster chooses the first 5 hosts that joins the cluster as primary nodes and all others hosts are automatically selected as secondary nodes.

How to see the list of Primary nodes in HA cluster?

View the log file named "aam_config_util_listnodes.log" under /var/log/vmware/aam using the below command

cat /var/log/vmware/aam/aam_config_util_listnodes.log

What is the command to restart /Start/Stop HA agent in the ESX host?

service vmware-aam restart

service vmware-aam stop

service vmware-aam start

Where to located HA related logs in case of troubleshooting?

/Var/log/vmware/aam

What the basic troubleshooting steps in case of HA agent install failed on hosts in HA cluster?

Below steps are are taken from my blog posts Troubleshooting HA

1. Check for some network issues

2. Check the DNS is configured properly

3. Check the vmware HA agent status in ESX host by using below commands

  service vmware-aam status

4. Check the networks are properly configured  and named exactly as other hosts in the cluster. otherwise, you will get the below errors while installing or reconfiguring HA agent.

5. Check HA related ports are open in firewall to allow for the communication
    
     Incoming port: TCP/UDP 8042-8045
     Outgoing port: TCP/UDP 2050-2250

6. First try to restart /stop/start the vmware HA agent on the affected host using the below commands. In addition ucan also try to restart vpxa and management agent in the Host.

        service vmware-aam restart

        service vmware-aam stop

        service vmware-aam start

7. Right Click the affected host and click on "Reconfigure for VMWare HA" to re-install the HA agent that particular host.

8. Remove the affected host from the cluster. Removing ESX host from the cluster will not be allowed untill that host is put into maintenance mode.

9.Alternative solution for 3 step is, Goto cluster settings and uncheck the vmware HA in to turnoff the HA in that cluster and re-enable the vmware HA to get the agent installed.

10. For further troubleshooting , review the HA logs under /Var/log/vmware/aam directory.


What is the maximum number of hosts per HA cluster?

Maximum number of hosts in the HA cluster is 32


What is Host Isolation?

VMware HA has a mechanism to detect a host is isolated from rest of hosts in the cluster. When the ESX host loses its ability to exchange heartbeat via management network between the other hosts in the HA cluster, that ESX host will be considered as a Isolated.

How Host Isolation is detected?

In HA cluster, ESX hosts uses heartbeats to communicate among other hosts in the cluster.By default, Heartbeat will be sent every 1 second.

If a ESX host in the cluster didn't received heartbeat for for 13 seconds from any other hosts in the cluster, The host considered it as isolated and host will ping the configured isolation address(default gateway by default). If the ping fails, VMware HA will execute the Host isolation response


What are the different types isolation response available in HA?

Power off –  All the VMs are powered off , when the HA detects that the network isolation occurs

Shut down – All VMs running on that host are shut down with the help of VMware Tools, when the HA detects that the network isolation occurs.If the shutdown via VMWare tools not happened within 5 minutes, VM's power off operation will be executed. This behavior can be changed with the help of HA advanced options. Please refer my Post on HA Advanced configuration


Leave powered on –  The VM's state remain powered on or remain unchanged, when the HA detects that the network isolation occurs.

How to add additional isolation address for redundancy?

By default, VMWare HA use to ping default gateway as the isolation address if it stops receiving heartbeat.We can add an additional values in case if we are using redundant service  console both belongs to different subnet.Let's say we can add the default gateway of SC1 as first value and gateway of SC2 as the additional one using the below value

1. Right Click your HA cluster

2. Goto to advanced options of HA

3. Add the line "das.isolationaddress1 = 192.168.0.1"

4. Add the line "das.isolationaddress2 = 192.168.1.1" as the additional isolation address

To know more about the Advanced HA Options

What is HA Admission control?

As per "VMware Availability Guide",

VCenter Server uses admission control to ensure that sufficient resources are available in a cluster to provide failover protection and to ensure that virtual machine resource reservations are respected.

What are the 2 types of settings available for admission control?

Enable: Do not power on VMs that violate availability constraints

Disable: Power on VMs that violate availability constraints


What are the different types of Admission control policy available with VMware HA?

There are 3 different types of Admission control policy available.

Host failures cluster  tolerates
Percentage of cluster resources reserved as fail over spare capacity
Specify a fail over host

How the Host Failures cluster tolerates admission control policy works?

Select the maximum number of host failures that you can afford for or to guarantee fail over. Prior vSphere 4.1, Minimum is 1 and the maximum is 4.

In the Host Failures cluster tolerates admission control policy , we can define the specific number of hosts  that can fail  in the cluster and also it ensures that the sufficient resources remain to fail over all the virtual machines from that failed hosts to the other hosts in cluster. VMware High Availability(HA) uses a mechanism called slots to calculate both the available and required resources in the cluster for a failing over virtual machines from a failed host  to other hosts in the cluster.

What is SLOT?

As per VMWare's Definition,

"A slot is a logical representation of the memory and CPU resources that satisfy the requirements for any powered-on virtual machine in the cluster."

If you have configured reservations at VM level, It influence the HA slot calculation. Highest memory reservation and highest CPU reservation of the VM in your cluster determines the slot size for the cluster.

How the HA Slots are Calculated?

I have written a post about how the HA slots are calculated.

How to Check the HA Slot information from vSphere Client?

Click on Cluster Summary Tab and Click on "Advanced Runtime Info" to see the the detailed HA slots information.

What is use of Host Monitoring  status in HA cluster?

Let's take an example, you are performing network maintenance activity on your switches which connects your one of thESX host in HA cluster.

what will happen if the switch connected to the ESX host in HA cluster is down?

It will not receive heartbeat and also ping to the isolation address also failed. so, host will think itself as isolated and HA will initiate the reboot of virtual machines on the host to other hosts in the cluster. Why do you need this unwanted situation while performing scheduled maintenance window.

To avoid the above situation when performing scheduled activity which may cause ESX host to isolate, remove the check box in " Enable Host Monitoring" until you are done with the network maintenance activity.


How to Manually define the HA Slot size?

By default, HA slot size is determined by the Virtual machine Highest CPU and memory reservation. If no reservation is specified at the VM level, default slot size of 256 MHZ for CPU and 0 MB + memory overhead for RAM will be taken as slot size. We can control the HA slot size manually by using the following values.

There are 4 options we can configure at HA advanced options related to slot size

das.slotMemInMB - Maximum Bound  value for HA memory slot size
das.slotCpuInMHz - Maximum Bound value for HA CPU slot Size
das.vmMemoryMinMB -  Minimum Bound  value for HA memory slot size
das.vmCpuMinMHz -  Minimum Bound  value for HA CPU slot size

For More HA related Advanced options, Please refer my blog post


How the "Percentage of cluster resources reserved as failover spare capacity" admission control policy works?

In the Percentage of cluster resources reserved as failover spare capacity admission control policy, We can define the specific percentage of total cluster resources are reserved for failover.In contrast to the "Host Failures cluster tolerates admission control policy", It will not use slots. Instead This policy calculates the in the way below


1.It calculates the Total resource requirement for all Powered-on Virtual Machines in the cluster  and also calculates the total resource available in host for virtual machines.
2.It calculates the current CPU and Memory Failover capacity for the capacity.
3.If the current CPU and Memory Failover capacity for the cluster < configured failover capacity (ex 25 %)
4.Admission control will not allow to power on the virtual machine which violates the availability constraints.


How the "Specify a failover host" admission control policy works?

In the Specify a failover host" admission control policy, We can define a specific host as a dedicated failover host. Whenisolation response is detected, HA attempts to restart the virtual machines on the specified failover host.In this Approach, dedicated failover hist will be sitting idle without actively involving or not participating in DRS load balancing.DRS will not migrate or power on placement of virtual machines on the defined failover host.


What is VM Monitoring status?

HA will usually monitors ESX hosts and reboot the virtual machine in the failed hosts in the other host in the cluster in case of host isolation but i need the HA to monitors for Virtual machine failures also. here the feature called VM monitoring status as part of HA settings.VM monitoring restarts the virtual machine if the vmware tools heartbeat didn't received with the specified time using Monitoring sensitivity.

If you are looking for more VMware interview questions Please click  Interview Questions.

Thanks For Reading!!! All the Best...

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How do we get virtualization?
Well there is no. of options available for this, but VMware, Citrix and Microsoft are front runners in domain. Here are the products from above for the same.
1. VMware ESX and VMware server
2. Citrix Xen
3. Microsoft Hyper-V
VMware Server:
VMware Server is a free virtualization product for Microsoft Windows and Linux servers. It enables you to quickly provision new server capacity or server consolidation by partitioning a Physical server into multiple virtual machines. It is meant for those businesses who want to optimize use of their technology assets using virtualization.

Technology behind VMware Server: 
• Hypervisor – 2 (Hosted Architecture)

What is Hosted Architecture?
Hosted architecture is where your virtualization software is installed as an application onto the pre-existing host operating system. This means that your virtualization layer relies on your host operating system for device support and physical resource management. VMware Server is a good example of a hosted architecture.

Hardware and Software support:
1. Any standard x86 compatible or x-86-64compatible personal computer
2. A wide variety of Windows, Linux, Solaris, and other guest operating systems,
Including 64-bit operating systems
3. Two-way Virtual SMP
4. Intel Virtualization Technology (Intel VT)
5. AMD-Virtualization (AMT-V)

Where VMware Server does fits for your environment?
VMware server suits the requirements and demands of small and medium scale business with non-mission critical processes. It can provide following options to the business resources.

1. Virtual Machines for software development: 
1. A common environment matching in both configuration and tools for your entire team
2. Quick rollout of new environments and tools
3. Archive of entire development environments for major projects

2. Virtual Machines for software testing: 
1. Platform Testing with Snapshots
2. Platform Testing with Persistent and Non-persistent Disks

3. Virtual Machines for Post-release and Application-Maintenance. 
1. It can create base image for you development environment
2. Archive of the development team’s virtual machines used during the development phase
3. Rapid platform availability for quick support tasks and bug investigation

4. Run Windows, Linux, and other operating systems and applications without
Software conflicts.
5. Move virtual machines from one physical host to another without having to
Reconfigure them.

Features of VMware Server:

1. Web-Based Interface

Use VMware Infrastructure Web Access (VI Web Access) to perform host and virtual machine configuration for VMware Server 2.0.
1. Create, configure, and delete virtual machines
2. Add and remove virtual machines from the inventory
3. Perform power operations (start, stop, reset, suspend, and resume) on virtual Machines
4. Monitor the operation of virtual machines
5. Generate a Web shortcut to customize the VI Web Access user interface for users, with the option to limit their view to the console or a single virtual machine
6. Generate a VMware Remote Console desktop shortcut that allows virtual machine users to interact directly with the guest operating system outside of a Web browser
7. Configure host-wide VMware Server settings


2. VMware Remote Console

VMware Remote Console enables you to interact with the guest operating system
running in a virtual machine. You can run VMware Remote Console on the host or a remote client system. After you install it as a Web browser add-on from VIWeb Access, VMware Remote Console can run independently from VIWeb Access.
VMware Remote Console also allows you to connect and disconnect client CD/DVD
and floppy devices.

3. Memory Support

The maximum amount of memory that can be allocated per virtual machine is
8GB. The amount of memory that can be used by all virtual machines combined is limited only by the amount of memory on the host computer.

4. Number of Network Adapters Supported

It can support total of 10 network adapters for a virtual machine.

5. Quiesced Backups of Virtual Machines on Windows

On Windows hosts, you can enable the VMware VSS Writer, which uses snapshots to
maintain the data integrity of applications running inside the virtual machine when
you take backups. 


6. Support for High-Speed USB 2.0 Devices

If the guest operating system has the appropriate USB 2.0 device drivers, you can use peripherals that require high-speed performance, such as speakers, webcams,
next-generation printers and scanners, fast storage devices, MP3 players, DVD-RW
drives, and high-capacity CD-ROM jukeboxes. 
Besides above there are few more such as 
• Additional host operating system support 
• Additional guest operating system support
• improved 64 bit guest support
• 64 bit sound driver
• Native 64 bit support on linux
• Improved VIX-API
• VMCI socket interface


Bottlenecks:
1. It puts more of your client's eggs in one basket. If the host machine breaks or needs to be taken offline, several virtual servers will go down.
2. Applications like databases that require a lot of disk activity. The prevailing wisdom is that databases should still run on dedicated physical servers.
3. Time-sensitive applications like Voice over IP (VoIP) may also be poor candidates for virtualization.
4. Virtual Machine overload: Application that are low I/O intensive and low utilization are best candidates for virtualization but need to put restriction on no. of virtual machines that can be handled with ease on physical server. 

VMware Server at a glance:

ESX Server
ESX Server is VMware’s flagship enterprise server virtualization platform. It comes in two versions – ESX Server and ESXi Server where the latter has no service console and is the thinnest version available. ESX Server has many optional features like VMotion and VMHA and some built-in features like the VMFS file system. Most end users purchase VMware ESX Server with some set of optional features in a package called VMware Infrastructure. ESX Server is managed by the VMware Infrastructure Client. Its centralized management platform is called Virtual Center.

Figure 1: ESX server in Enterprise (Virtual infrastructure)

What is the need of ESX Server?
If you are an idealist then ESX is just for you. It possesses best approaches to adopt the hardware abstraction and most effective usage of your resources through vast available tools and services so that you can maximize your infrastructure efficiency, reducing operational cost by providing cost effective business continuity.

Technology behind ESX:
• Hypervisor – 1 (Bare Metal) 
Bare Metal means no OS is required because it has its own kernel derived from linux withit provides greater resources for the virtual machines, decreased cost of licensing and increased utilization of servers.

Where ESX server does fit for your environment?

As ESX is enterprise wide solution for virtualization to adopt effective hardware abstraction, it best suits for large enterprises with enormous resources.

Hardware and Software support with Features for ESX:

Architecture:
1. Bare-metal architecture: VMware ESX inserts a robust virtualization layer directly on the server hardware for near-native virtual machine performance, reliability and scalability.

Fig: Hypervisor (Baremetal)

2. Small Footprint: VMware ESXi’s 32MB disk footprint is a fraction of the size of a general purpose operating system, reducing complexity and providing unmatched security and reliability. 

3. Server Integration: VMware ESXi is available built into server hardware as an embedded component, simplifying and speeding deployment of virtualization. 

4. CPU virtualization: Increase server utilization without the risk of critical services being starved for CPU resources. VMware ESX uses intelligent process scheduling and load balancing across available processors to manage the execution of virtual machine processing. 

5. Storage in ESX Server: Leverage high performance shared storage to centralize virtual machine file storage for greater manageability, flexibility and availability. 
• Virtual disk files: Add or delete a VMware ESX server from a VMFS volume without pausing or halting the processing of other instances of VMware ESX 
• VMFS cluster file system: Leverage high performance shared storage to centralize virtual machine file storage for greater manageability, flexibility and availability 
• Logical volume manager: Manage the interaction between the physical storage arrays and VMFS with flexibility and reliability 
• Raw device mapping: Optionally, map SAN LUNs directly to a virtual machine in order to enable application clustering and array-based snapshot technology while profiting from the manageability benefits of VMFS 
• Fiber Channel HBA consolidation: Share expensive storage network components across many virtual machines while maintaining hardware fault tolerance 
• Write-through I/O: Ensure precise recovery of virtual machines in the event of server failure. Write-through I/O enables virtual machines to have the same recovery characteristics as a physical system running the same operating system. 
• Boot from SAN: Run VMware ESX installations on diskless configurations of blade and rack mount servers by booting from SAN. Simplify backups and disaster recovery by eliminating the need to separately backup local attached server disks


VMFS: (Virtual Machine File System) VMware Virtual Machine File System is a high performance cluster file system which provides storage virtualization that is optimized for virtual machines. Each virtual machine is encapsulated in a small set of files; and VMFS is the default storage management interface for these files on physical SCSI disks and partitions.

Fig: VMFS allows sharing of storage for multiple ESX servers


Features of VMFS:
The technical features of VMFS that make it suitable for use in a virtual environment include:
1. Automated file system with hierarchical directory structure
2. Optimization for virtual machines in a clustered environment
3. Lock management and distributed logical volume management
4. Dynamic datastore expansion by spanning multiple storage extents
5. Clustered file system with journal logging for fast recovery
6. Encapsulation of the entire virtual machine state in a single directory

Benefits of VMFS:
1. Automated Cluster File System Capability
2. Optimizes VM Access
3. Encapsulates the Entire VM State in a Single Directory
4. Simplifies Provisioning and Administration of VMs
5. Provides Distributed Infrastructure Services for Multi-ESX Servers
6. Facilitates Dynamic Growth
7. Intelligent Cluster Volume Management
8. Enables HA with Lower Management Overhead
9. Simplifies Disaster Recovery

VMFS V/S other file systems:
Conventional file systems allow only one server to have read-write access to the same file at a given time. In contrast, VMFS is a cluster file system that leverages shared storage to allow multiple instances of ESX Server concurrent read and write access to the same storage resources. VMFS also has distributed journaling to allow fast and resilient recovery across these multi-server resource pools.

On-disk locking in VMFS ensures that a virtual machine is not powered on by multiple installations of ESX Server at the same time. With VMware HA enabled, if a server fails the on-disk lock for each virtual machine is released, allowing the virtual machine to be restarted on other physical servers. Moreover, VMFS provides the VM snapshot capabilities so necessary for disaster recovery, and is the interface which VMware Consolidated Backup (VCB) leverages to provide proxy backup of virtual environments.

VMFS does not have every feature found today in other CFS and CVM systems. However there is no other CFS/CVM that provides the capabilities of VMFS. Its distributed locking methods forge the link between the VM and the underlying storage resources in a manner that no other CFS or CVM can equal. The unique capabilities of VMFS allow VMs to join a cluster seamlessly, with no management overhead.


6. Networking in ESX Server: Network virtual machines like physical machines. Build complex networks within a single VMware ESX server or across multiple installations of VMware ESX for production deployments or development and testing purposes. 
• Virtual NICs: Configure each virtual machine with one or more virtual NICs. Each of those network interfaces can have its own IP address and even its own MAC address. As a result, virtual machines are indistinguishable from physical machines from a networking standpoint 
• Virtual switches: Create a simulated network within a VMware ESX server with virtual switches that connect virtual machines. 
• Expanded port configuration policies: Simplify port configuration by utilizing a single configuration object across large groups of ports. The configuration object specifies all information needed to enable a port: NIC teaming policy (now per port instead of per virtual switch), VLAN tagging, Layer 2 security, and traffic shaping. 
• VLAN: Overlay a logical LAN on top of physical LANs to isolate network traffic for security and load segregation purposes. VMware ESX VLANs are compatible with standard VLAN implementations from other vendors. Modify network configurations without having to change actual cabling and switch setups. VLANs keep broadcast traffic limited to the VLAN, reducing the network load of broadcast packets on other switches and network segments. 

Performance and Scalability:

VMware ESX delivers unparalleled performance and scalability. With VMware ESX, even the most resource intensive production applications such as databases, ERP and CRM can be virtualized. 
1. Enhanced virtual machine performance: Benefit from better virtual machine performance in VMware ESX. Performance improvements have been achieved through: 
• Networking performance optimization: Reduce the CPU overhead associated with processing network i/ 
• Support for hardware nested page tables: Optimize memory translation time between guest operating systems and physical memory 
• Support for large memory pages: Improve memory access efficiency for guest operating systems and the Hypervisor 
• Support for Para virtualized Linux guest operating systems (Linux kernel 2.6.21 onwards). Run higher levels of performance through virtualization-aware operating systems



2. Advanced memory management:
• RAM over-commitment: Increase memory utilization by configuring virtual machine memory that safely exceeds the physical server memory. For example, the sum of the memory of all virtual machines running on a server with 8GB physical memory can be 16GB 
• Transparent page sharing: Utilize available memory more efficiently by storing memory pages identical across multiple virtual machines only once. For example, if several virtual machines are running Windows Server 2003, they will have many identical memory pages. Transparent page sharing consolidates those identical pages into a single memory location. 
• Memory ballooning: Shift memory dynamically from idle virtual machines to active ones. Memory ballooning artificially induces memory pressure within idle virtual machines, forcing them to use their own paging areas and release memory for active virtual machines.

3. Improved power management: Lower the data center utility bill with improved power management. VMware ESX enters a low power “halt” state when a CPU is not scheduled. 

4. 4-Way Virtual SMP(Symmetric multiple processor): Enable a single virtual machine to use up to four physical processors simultaneously. VMware ESX extends this unique feature from two to four processors. With 4-way Virtual SMP even the most processor intensive software applications like databases and messaging servers can be virtualized. 

5. 64GB RAM for virtual machines: Run the most memory-intensive workloads in virtual machines with a memory limit extended to 64GB. 

6. Support for powerful physical server systems: Take advantage of very large server systems with up to 32 logical CPUs and 256GB RAM for large scale server consolidation and DR projects. 

7. Support for up to 128 powered-on virtual machines: Take advantage of very large server systems for enterprise-class server consolidation and containment with support for up to 128 powered on virtual machines on a single server. 

8. Flexible virtual switches: Scale up to handle more virtual machines. Virtual switches can be created with any number of ports from 8 to 1016, and up to 248 virtual switches are supported per host. 

9. Wake-on LAN: Enable higher consolidation ratios by allowing virtual machines to go on stand-by mode when not used.


Interoperability:

VMware ESX is the only virtualization platform optimized, rigorously tested and certified across the complete IT stack of servers, storage, operating systems, and software applications allowing for enterprise-wide standardization. 

1. Hardware: VMware ESX has been certified with industry-leading rack, tower and blade servers from Dell, Fujitsu Siemens, HP, IBM, NEC, Sun Microsystems and Unisys as well as servers that conform to Intel white-box standard specifications. 
VMware ESXi is integrated into server hardware guaranteeing that virtualization works out of the box. 

2. Storage: VMware ESX is certified with a wide range of storage systems from, Dell, EMC, EqualLogic, Fujitsu, Fujitsu Siemens, HP, Hitachi Data Systems, IBM, NEC, Network Appliance, StorageTek, Sun Microsystems and 3PAR and many other vendors. 
• Heterogeneous storage arrays: Utilize a wide variety of heterogeneous storage devices in the same VMFS volume 
• NAS and iSCSI SAN support: By supporting lower-cost, more easily managed shared storage, VMware ESX further reduces total cost of ownership of IT environments. Advanced VMware Infrastructure features like VMotion and VMware HA are fully supported with NAS and iSCSI environments 
• 4GB Fibre Channel SAN support: Centralize management and configuration of all VMware ESX servers in VirtualCenter. 
• Local SATA storage support: Use select servers with local SATA storage to further lower total cost of ownership while consolidating workloads

3. Networking: Use high performance networking such as 10 Gig E and Infiniband with VMware ESX 3.5 and VMware ESXi 3.5 for the most network intensive workloads 

4. Operating systems: Run any software application in VMware virtual machines. 
• 64-bit guest operating system suppor 
• Solaris 10 operating system suppor 
• Windows Vista operating system support 
• Ubuntu guest operating system support

5. Software applications with third party systems management products through Web services APIs provided by the VMware Infrastructure SDK. 

6. Support for other virtual machine formats: VMware ESX can run virtual machines created in non-VMware formats. Using the free VMware Virtual Machine Importer users can run Microsoft® Virtual Server and Virtual PC, and Symantec® LiveState Recovery virtual machines in VMware ESX.


Management:

1. Remote Command Line Interface. Manage VMware ESXi through a remote execution environment that can run VMware ESX command scripts. 

2. Advanced manageability and usability features: VMware ESX enables management of entire virtualized IT environment. 

3. SMI-S-Compliant Management Interfaces: Monitor virtual storage using any standard SMI-S-aware storage management tool. 

4. Virtual Infrastructure Client: Manage VMware ESX, virtual machines, and (optionally) VMware vCenter Server with a common user interface.

5. Virtual Infrastructure Web Access: Manage VMware ESX with simple Web interface (formerly known as the Management User Interface, or MUI). 

6. Virtual machine shortcuts: Enable self-help for end users with direct access to virtual machines through a Web browser. 

7. Remote devices: Install software in a virtual machine running on a server from the CD-ROM of a desktop without leaving your desk. 

8. Agent-less Hardware Management with CIM: The Common Information Model (CIM) provides a protocol for monitoring hardware health and status through VirtualCenter or CIM-compatible 3rd party tools.


Resource Optimization:

It defines advanced resource allocation policies for virtual machines to improve service levels to software applications. Establish minimum, maximum, and proportional resource shares for CPU, memory, disk and network bandwidth. Modify allocations while virtual machines are running. Enable applications to dynamically acquire more resources to accommodate peak performance. 

1. CPU capacity prioritization: CPU capacity is assigned to virtual machines on a “fair share” basis and CPU resource controls also allow an absolute minimum level of CPU capacity to be provided to critical virtual machines 

2. Storage I/O traffic prioritization: Ensure that critical virtual machines receive priority access to storage devices. I/O traffic from virtual machines to disk can be prioritized on a “fair share” basis. 

3. Network Traffic Shaper: Ensure that critical virtual machines receive priority access to network bandwidth. Network traffic from virtual machines can be prioritized on a “fair share” basis. Network Traffic Shaper manages virtual machine network traffic to meet peak bandwidth, average bandwidth and burst size constraints.

4. Resource Pool: Aggregate collections of hardware resources virtualized by VMware ESX into unified logical resources that can be allocated to virtual machines on-demand. Resource pools increase flexibility and hardware utilization. 

Security:

1. Compatibility with SAN security practices: Enforce security policies with LUN zoning and LUN masking. 

2. VLAN tagging: Enhance network security by tagging and filtering network traffic on VLANs. Limit the scope of broadcast domains. 

3. Layer 2 network security policies: Enforce security for virtual machines at the Ethernet layer. Disallow promiscuous mode sniffing of network traffic, MAC address changes, and forged source MAC transmits.


ESX VCB(VMware Consolidated backup): 

VCB is a group of Windows command line utilities, installed on a Windows system, that has SAN connectivity to the ESX Server VMFS file system. With VCB, you can perform file level or image level backups and restores of the VM guests, back to the VCB server. FFf

VmWare Interview Questions With Answers

VMware 4.1 Questions
1. What is HA?
VMware HA delivers the availability needed by many applications running in virtual machines, independent of the operating system and application running in it. VMware HA provides uniform, cost-effective failover protection against hardware and operating system failures within your virtualized IT environment.
• Monitors virtual machines to detect operating system and hardware failures.
• Restarts virtual machines on other physical servers in the resource pool without manual intervention when server failure is detected.
• Protects applications from operating system failures by automatically restarting virtual machines when an operating system failure is detected.

2. How HA works?
VMware HA continuously monitors all servers in a resource pool and detects server failures. An agent placed on each server maintains a “heartbeat” with the other servers in the resource pool and a loss of “heartbeat” initiates the restart process of all affected virtual machines on other servers. VMware HA ensures that sufficient resources are available in the resource pool at all times to be able to restart virtual machines on different physical servers in the event of server failure. Restart of virtual machines is made possible by the Virtual Machine File System (VMFS) clustered file system which gives multiple ESX Server instances read-write access to the same virtual machine files, concurrently. VMware HA is easily configured for a resource pool through VirtualCenter.
Key Features of VMware HA

• Automatic detection of server failures. Automate the monitoring of physical server availability. HA detects server failures and initiates the virtual machine restart without any human intervention.

• Resource checks. Ensure that capacity is always available in order to restart all virtual machines affected by server failure. HA continuously monitors capacity utilization and “reserves” spare
capacity to be able to restart virtual machines.

• Automatic restart of virtual machines. Protect any application with automatic restart in a different physical server in the resource pool.

• Intelligent choice of servers (when used with VMware Distributed Resource Scheduler (DRS)). Automate the optimal placement of virtual machines restarted after server failure.

The VMware HA Solution
With VMware HA, a set of ESX Server hosts is combined into a cluster with a shared pool of resources. VMware HA monitors all hosts in the cluster. If one of the hosts fails, VMware HA immediately responds by restarting each affected virtual machine on a different host.

Using VMware HA has a number of advantages:
• Minimal setup and startup. The New Cluster wizard is used for initial setup. Hosts and new virtual machines can be added using the Virtual Infrastructure Client.
• Reduced hardware cost and setup. In a traditional clustering solution, duplicate hardware and software must be available, and the components must be connected and configured properly. When using VMware HA clusters, you must have sufficient resources to accommodate the number of hosts for which you want to guarantee failover. However, the VirtualCenter Server takes care of all other aspects of the resource management.
• VMware HA "democratizes" high availability by making it available and cost-justifiable for any application, regardless of hardware and operating system platform. VMware HA is focused on hardware failure, not on operating system or software failure. If you need greater levels and guarantees of availability to handle those situations, you can consider using both VMware HA and traditional high availability approaches together.

VMware HA Features
Using a cluster enabled for VMware HA provides the following features:
• Automatic failover is provided on ESX Server host hardware failure for all running virtual machines within the bounds of failover capacity.
VMware HA provides automatic detection of server failures and initiates the virtual machine restart without any human intervention.
• VMware HA can take advantage of DRS to provide for dynamic and intelligent resource allocation and optimization of virtual machines after failover. After a host has failed and virtual machines have been restarted on other hosts, DRS can provide further migration recommendations or migrate virtual machines for more optimum host placement andbalanced resource allocation.
• VMware HA supports easy-to-use configuration and monitoring using VirtualCenter. HA ensures that capacity is always available (within the limits of specified failover capacity) in order to restart all virtual machines affected by server failure (based on resource reservations configured for the virtual machines.)
• HA continuously monitors capacity utilization and "reserves" spare capacity to be able to restart virtual machines. Virtual Machines can fully utilize spare failover capacity when there hasn't been a failure.

3. What is DRS?

Align Resources to Meet Business Needs
VMware DRS continuously monitors utilization across resource pools and intelligently aligns resources with business needs, enabling us to:
• Dynamically allocate IT resources to the highest priority applications. Create rules and policies to prioritize how resources are allocated to virtual machines.
• Give IT autonomy to business organizations. Provide dedicated IT infrastructure to business units while still achieving higher hardware utilization through resource pooling.
• Empower business units to build and manage virtual machines within their resource pool while giving central IT control over hardware resources.

Balance Your Computing Capacity
VMware DRS continuously balances computing capacity in resource pools to deliver the performance, scalability and availability not possible with physical infrastructure. VMware DRS allows us to:
• Improve service levels for all applications. VMware DRS continuously balance capacity will ensure that each virtual machine has access to appropriate resources at any point in time.
• Easily deploy new capacity. VMware DRS will seamlessly take advantage of the additional capacity of new servers added to a resource pool by redistributing virtual machines without system disruption.
• Automate planned server maintenance. VMware DRS can automatically migrate all virtual machines off physical servers to enable scheduled server maintenance with zero downtime.
• Dramatically increase system administrator productivity. Enable system administrators to monitor and effectively manage more IT infrastructure.

Reduce Energy Consumption in the Datacenter
VMware Distributed Power Management (DPM) continuously optimizes power consumption in the datacenter. When virtual machines in a DRS cluster need fewer resources, such as during nights and weekends, DPM consolidates workloads onto fewer servers and powers off the rest to reduce power consumption. When virtual machine resource requirements increase (such as when users log into applications in the morning), DPM brings powered-down hosts back online to ensure service levels are met.
VMware Distributed Power Management allows IT organizations to:
• Cut ongoing power and cooling costs by up to 20% in the datacenter during low utilization time periods.
• Automate management of energy efficiency in the datacenter
VMware DRS (with DPM) is included in the VMware vSphere Enterprise and Enterprise Plus edition. DRS and DPM leverage VMware vMotion (live migration) to balance load and optimize power consumption with no downtime.
Features
The following is a list of the key features of VMware DRS.
• Aggregation of physical server resources. Manage CPU and memory across a group of physical servers as a uniform shared pool of resources.
• Flexible hierarchical organization. Organize resource pools hierarchically to match available IT resources to the business organization. VMware DRS ensures that resource utilization is maximized while business units retain control and autonomy of their infrastructure. Resource pools can be flexibly added, removed, or reorganized as business needs or organization change.
• Priority Settings. Assign priorities in the form of shares or reservations to virtual machines within resource pools and to sub resource pools to reflect business priorities. For example, the production sub resource pool can have higher shares of the total resources in a cluster and business critical applications within the production resource pool can have fixed guarantees(reservations) of CPU bandwidth and memory,
• Management of sets of virtual machines running a distributed application. Optimize the service level of distributed applications by controlling the aggregate allocation of resources for the entire set of virtual machines running the distributed application.
• Affinity Rules. Create rules that govern placement of virtual machines on physical servers. For example, a group of virtual machines can be set to always run on the same server for performance reasons. Alternatively, certain virtual machines can be set to always run on different servers to increase availability. New in vSphere 4.1 is the ability to restrict placement of virtual machines to a group of physical servers in a cluster. This is useful for controlling the mobility of virtual machines that run software licensed for a specific group of physical servers. In addition, this feature can be used to keep sets of virtual machines on different racks or blade systems for availability reasons.
• Power Management. Reduce energy consumption in the datacenter by using the Distributed Power Management (DPM) feature of DRS to consolidate workloads and power off servers when they are not needed by the virtual machines in the cluster. When resource requirements of virtual machines increase, DPM brings hosts back online so service levels can be met.
• Manual and Automatic Mode. VMware DRS collects resource usage information from servers and virtual machines, and then generates recommendations to optimize virtual machine allocation. These recommendations can be executed automatically or manually.
o Initial placement. When a virtual machine is first powered on, VMware DRS either automatically places the virtual machine on the most appropriate physical server or makes a recommendation.
o Continuous optimization. VMware DRS continuously optimizes resource allocations based on defined resource allocation rules and resource utilization. The resource allocation changes can be automatically executed by performing live migration of virtual machines through vMotion. Alternatively, in manual mode, VMware DRS provides execution recommendations for system administrators.
• Maintenance mode for servers. Perform maintenance on physical servers without disruption to virtual machines and end users. When a physical server is placed in maintenance mode, VMware DRS identifies alternative servers where the virtual machines can run. Based on automation mode settings, the virtual machines are either automatically moved to use the alternative servers, or the system administrator performs the move manually using the VMware DRS recommendations as a guideline.
• Large-scale management. Manage CPU and memory across up to 32 servers and 1280 virtual machines per DRS cluster.

4. What is vMotion?

Experience Game-changing Virtual Machine Mobility
VMware vMotion technology, leverages the complete virtualization of servers, storage and networking to move an entire running virtual machine instantaneously from one server to another. VMware vMotion uses VMware’s cluster file system to control access to a virtual machine’s storage. During a vMotion, the active memory and precise execution state of a virtual machine is rapidly transmitted over a high speed network from one physical server to another and access to the virtual machines disk storage is instantly switched to the new physical host. Since the network is also virtualized by the VMware host, the virtual machine retains its network identity and connections, ensuring a seamless migration process.

VMware vMotion allows you to:
• Perform live migrations with zero downtime, undetectable to the user.
• Continuously and automatically optimize virtual machines within resource pools.
• Perform hardware maintenance without scheduling downtime and disrupting business operations.
• Proactively move virtual machines away from failing or underperforming servers.



Reliably Manage Live Migrations with Ease
Benefit from the reliability and manageability derived from a production-proven product used by thousands of customers for years. Live migration of virtual machines across your infrastructure is surprisingly simple with functionality that lets you:
• Perform multiple concurrent migrations to continuously optimize a virtual IT environment.
• Identify the optimal placement for a virtual machine in seconds with a migration wizard providing real-time availability information.
• Migrate any virtual machine running any operating system across any type of hardware and storage supported by vSphere, including Fibre Channel SAN, NAS and iSCSI SAN.
• Prioritize live migrations to ensure that mission-critical virtual machines maintain access to the resources they need.
• Schedule migrations to happen at pre-defined times, and without an administrator’s presence.
• Maintain an audit trail with a detailed record of migrations.

How Does VMware VMotion Work?

Live migration of a virtual machine from one physical server to another with VMware VMotion is enabled by three
underlying technologies.

First, the entire state of a virtual machine is encapsulated by a set of files stored on shared storage such as Fibre Channel or iSCSI Storage Area Network (SAN) or Network Attached Storage (NAS). VMware vStorage VMFS allows multiple installations of VMware ESX® to access the same virtual machine files concurrently.

Second, the active memory and precise execution state of the virtual machine is rapidly transferred over a high speed network, allowing the virtual machine to instantaneously switch from running on the source ESX host to the destination ESX host. VMotion keeps the transfer period imperceptible to users by keeping track of on-going memory transactions in a bitmap.
Once the entire memory and system state has been copied over to the target ESX host, VMotion suspends the source virtual machine, copies the bitmap to the target ESX host, and resumes the virtual machine on the target ESX host. This entire process takes less than two seconds on a Gigabit Ethernet network.

Third, the networks being used by the virtual machine are also virtualized by the underlying ESX host, ensuring that even after the migration, the virtual machine network identity and network connections are preserved. VMotion manages the virtual MAC address as part of the process. Once the destination machine is activated, VMotion pings the network router to ensure that it is aware of the new physical location of the virtual MAC address.
Since the migration of a virtual machine with VMotion preserves the precise execution state, the network identity, and the active network connections, the result is zero downtime and no disruption to users.

Key Features of vMotion.

Reliability.
Proven by thousands of customers in production environments since 2004, VMotion continues to set the standard for the most dependable live migration capabilities.

Performance.
Perform live migrations with downtime unnoticeable to the end users. Optimal use of CPU and network resources ensures that the live migrations occur quickly and efficiently.

Interoperability.
Migrate virtual machines running any operating system across any type of hardware and storage supported by VMware ESX.
• Support for Fibre Channel SAN.
Implement live migration of virtual machines utilizing a wide range of up to 4GB Fibre Channel SAN storage systems.
• NAS and iSCSI SAN support. Implement live migration of virtual machines with lower-cost,
more easily managed shared storage.
• Customizable CPU compatibility settings. Ensure that virtual machines can be migrated across different
versions of hardware. Enable virtual machines to benefit from the latest CPU innovations.
• New - Enhanced VMotion Compatibility. Live migrate virtual machines across different generations of
hardware. Migrate virtual machines from older servers to new ones without disruption or downtime.

Manageability
• Migration wizard.
Quickly identify the best destination for a virtual machine using real-time information provided by migration wizard.
• Multiple concurrent migrations.
Perform multiple concurrent migrations to continuously optimize virtual machine placement across the entire
IT environment.
• Priority levels.
Assign a priority to each live migration operation to ensure that the most important virtual machines always have access to the resources they need.
• Scheduled migration tasks.
Automate migrations to happen at pre-defined times, and without an administrator’s presence.
• Migration audit trail.
Maintain a detailed record of migration operations, including date/time and the administrators responsible for initiating them.

5. What is VMware Storage VMotion?

VMware Storage VMotion is a component of VMware vSphere™ that provides an intuitive interface for live migration of virtual machine disk files within and across storage arrays with no downtime or disruption in service. Storage VMotion relocates virtual machine disk files from one shared storage location to another shared storage location with zero downtime, continuous service availability and complete transaction integrity. Storage VMotion enables organizations to perform proactive storage migrations, simplify array migrations, improve virtual machine
storage performance and free up valuable storage capacity. Storage VMotion is fully integrated with VMware vCenter Server to provide easy migration and monitoring.

How is VMware Storage VMotion Used in the Enterprise?

Customers use VMware Storage VMotion to:

• Simplify array migrations and storage upgrades.
The traditional process of moving data to new storage is cumbersome, time-consuming and disruptive. With Storage VMotion, IT organizations can accelerate migrations while minimizing or eliminating associated service disruptions, making it easier, faster and more cost-effective to embrace new storage platforms and file formats, take advantage of flexible leasing models, retire older, hard-to-manage storage arrays and to conduct storage upgrades and migrations based on usage and priority policies. Storage VMotion works with any operating system and storage hardware platform supported by VMware ESX™, enabling customers to use a heterogeneous mix
of datastores and file formats.

• Dynamically optimize storage I/O performance.
Optimizing storage I/O performance often requires reconfiguration and reallocation of storage, which can be a
highly disruptive process for both administrators and users and often requires scheduling downtime. With Storage
VMotion, IT administrators can move virtual machine disk files to alternative LUNs that are properly configured to
deliver optimal performance without the need for scheduled downtime, eliminating the time and cost associated with traditional methods.

• Efficiently manage storage capacity.
Increasing or decreasing storage allocation requires multiple manual steps, including coordination between groups, scheduling downtime and adding additional storage. This is then followed by a lengthy migration of virtual machine disk files to the new datastore, resulting in significant service downtime. Storage VMotion improves this process by enabling administrators to take advantage of newly allocated storage in a non-disruptive manner. Storage VMotion can also be used as a storage tiering tool by moving data to different types of storage platforms based the data value, performance requirements and storage costs.

How Does VMware Storage VMotion Work?

VMware Storage VMotion allows virtual machine storage disks to be relocated to different datastore locations with no downtime, while being completely transparent to the virtual machine or the end user.

Before moving a virtual machines disk file, Storage VMotion moves the “home directory” of the virtual machine to the new location. The home directory contains meta data about the virtual machine (configuration, swap and log files). After relocating the home directory, Storage VMotion copies the contents of the entire virtual machine storage disk file to the destination storage host, leveraging “changed block tracking” to maintain data integrity during the migration process. Next, the software queries the changed block tracking module to determine what regions of the disk were written to during the first iteration, and then performs a second iteration of copy, where those regions that were changed during the first iteration copy (there can be several more iterations).

Once the process is complete, the virtual machine is quickly suspended and resumed so that it can begin using the virtual machine home directory and disk file on the destination datastore location. Before VMware ESX allows the virtual machine to start running again, the final changed regions of the source disk are copied over to the destination and the source home and disks are removed.

This approach guarantees complete transactional integrity and is fast enough to be unnoticeable to the end user.

Key Features of VMware Storage VMotion

Complete transaction integrity.
No interruption or downtime for users and applications during virtual machine storage disk migrations.

Interoperability.
Storage VMotion can migrate storage disk files for virtual machines running any operating system across any type of hardware and storage supported by VMware ESX.









1) How we manage the licenses, i.e. timely updating licenses, briefly explain?


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2) If we found HA issue, what are steps we should follow to resolve the issues?

To troubleshoot HA errors:

Note: Most of these troubleshooting steps are done on the ESX console.
1.Run this command to verify that host name is in lowercase and is fully qualified:

hostname


2.Run this command to verify that hostname is shortname only and is in lowercase:

hostname –s


3.Run this command to verify that the correct service console IP is displayed:

hostname –i


4.Verify that the host name in /etc/hosts is lowercase and both FQDN and shortname are present.
5.Verify that the search domain is present in the /etc/resolv.conf file and is in lowercase.
6.Verify that the host name in /etc/sysconfig/network is FQDN and is in lowercase.
7.Verify that the host name in the /etc/vmware/esx.conf file is FQDN and is in lowercase.
8.Verify that the system name returned by the uname -a command is in lowercase.
9.Verify that the host name is in your DNS server and is in lowercase. To do this, run these commands:
a.nslookup

Where is the name of the host.

This command should return the service console IP.


b.nslookup

Where is the FQDN name of the host.

This command should return the service console IP.


c.nslookup

Where is the IP address of the host.

This command should return the FQDN of the host


10.Make sure the route for the service console is correct. To do this, from each host, ping the other hosts in the environment.
11.Verify that all primary service consoles have the same name.
12.Verify that all primary service consoles are in the same IP subnet.
13.If the vmkernel port group of vMotion is on same vSwitch as primary Service Console port group, add das.allowVmotionNetworks=1 to the advanced settings of
HA.
14.If the host has multiple service consoles, add das.allowNetwork0 to the Advanced HA Settings of the cluster to ensure that only the primary service
console is allowed. For more information, see Incompatible HA Networks appearing when attempting to configure HA (High Availability) (1006541).
15.Verify that you have the appropriate licenses available for HA. To do this, in LM Tools, perform a status enquiry and verify that you have VC_DAS licenses
available.
If you are unable to configure HA after verifying these troubleshooting steps:
1.Run this command on the ESX host to stop vpxa:

service vmware-vpxa stop

The host appears as not responding in the vCenter Server after a while.


2.Run these commands to uninstall aam:
1.rpm -qa | grep aam
2.rpm -e (package names output from command above)
3.rpm -e (other package names output from command above)
4.find / -name aam

Note: Ensure to delete the directories listed by this command.


3.Disconnect the ESX host from the vCenter Server.
4.Re-connect the host to the vCenter Server. This forces the VPXA package and the the HA packages to re-deploy.
5.Re-configure all the hosts for HA.
6.Upgrade to ESX 3.5 U4 or later and vCenter Server 2.5U4 or later.
7.After upgrading, add das.bypassNetCompatCheck=true to the Advanced HA Settings of the cluster, if it continues to have issues.
If your issue continues to exist after performing these steps, contact your network or storage administrator.

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3) Redundancy between NICs in an ESX server & how many minimum NICs required for esx


-----------------------------------------------------------------------------------------------------------------------
4) Minimum requirements for VMotion configure?


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5) How licenses calculated/purchased for VMware environment?


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6) What are the partitions of an ESX server?

Service Console Partitions and Sizes for Each ESX Server Host

Mount Point Partition Size Description

/dev/sda (Primary)

/boot ext3 250 MB Change for additional space for upgrades

N/A swap 1600 MB Change for maximum service console swap size

/ ext3 5120 MB Change for additional space in root

/dev/sda (Extended)

/var ext3 4096 MB Create partition to avoid overfilling root with log files

/tmp ext3 1024 MB Create partition to avoid overfilling root with temporary files

/opt ext3 2048 MB Create partition to avoid overfilling root with VMware HA log files

/home ext3 1024 MB Create partition to avoid overfilling root with agent / user files

vmkcore 100 MB Pre-configured

Free Space (Optional) Auto-configured and used for local VMFS-3 volume (needed for virtual machines running Microsoft’s Clustering Software.


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7) Whether we need licenses for HA, DRS feature?
Yes,

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8) What should be the main reason for purple screen errors?

Purple Screen of Death

A Purple Screen of Death as seen in VMware ESX Server 3.0 In the event of a hardware error, the vmkernel can 'catch' a Machine Check Exception.This results
in an error message displayed on a purple console screen. This is colloquially known as a PSOD, or Purple Screen of Death.

Upon displaying a PSOD, the vmkernel writes debug information to the core dump partition. This information, together with the error codes displayed on the
PSOD can be used by VMware support to determine the cause of the problem.



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9) How to configure virtual switches & what is port-group & what is VLAN?


-----------------------------------------------------------------------------------------------------------------
10) Whether HA use VMotion or not?

No, it requires DRS.

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11) Whether DRS use VMotion or not?

yes

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12) What are processes & port numbers for virtual center, HA running in ESX?

Ports and descriptions:

80 – Required for direct HTTP connections. Port 80 redirects requests to HTTPS port 443.

443 - Listens for connections from the vSphere Client, vSphere Web Access Client, and other SDK clients. Open port 443 in the firewall to enable the vCenter
Server system to receive data from the vSphere Client.

389 - This port is used for Lightweight Directory Access Protocol (LDAP) services. Who says LDAP, says Active Directory Services for the vCenter Server
group.

636 – SSL port of the local instance for vCenter Linked Mode. It’s the port of the local vCenter Server ADAM Instance.

902 - Used to send data to managed hosts. To send data to your ESX or ESXi hosts. Also this port is used for remote console access to virtual machines from
vSphere Client. This port must not be blocked by firewalls between the server and the hosts or between hosts.

902/903 - Used by the vSphere Client to display virtual machine consoles.

8080 – vCenter Management Webservices HTTP.

8443 - Secure connections for vCenter Management Webservices HTTPS.

60099 - Used to stream inventory object changes to SDK clients. Firewall rules for this port on the vCenter Server can be set to block all, except from and
to localhosts if the clients are installed on the same host as the vCenter Server service.

--------Various services are installed when you deploy vCenter, in total 5 services are installed----------

1.VMware VirtualCenter Server: Heart of vCenter
2.VMware mount service for VirtualCenter: used during cloning operation or while deploying from template
3.VMware VirtualCenter management webservices: Web management services run on it.
4.VMwareVCMSDS:ADAM services for linked mode
5.VMware vCenter orchestrator configuration: use for vCenter orchestrator

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13) In ESX2.5.2 how we take backups of vm files?


----------------------------------------------------------------------------------------------------------------------
14) Explain the purpose of Redo log files?


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15) VM is not able to power off, how to trouble shoot d issues?

Powering off the virtual machine

To determine if you must use the command line, attempt to power off the virtual machine:
1.Connect VMware Infrastructure (VI) Client to the Virtual Center Server. Right-click on the virtual machine and click Power off.
2.Connect VI Client directly to the ESX host. Right-click on the virtual machine and click Power off.

If this does not work, you must use the command line method.
Determining the virtual machine's state
1.Determine the host on which the virtual machine is running. This information is available in the virtual machine's Summary tab when viewed in the VI Client
page.
2.Log in as root to the ESX host using an SSH client.
3.Run the following command to verify that the virtual machine is running on this host:

# vmware-cmd -l

The output of this command returns the full path to each virtual machine running on the ESX host. Verify that the virtual machine is listed, and record the
full path for use in this process. For example:

# /vmfs/volumes///.vmx


4.Run the following command to determine the state in which the ESX host believes the virtual machine to be operating:

# vmware-cmd getstate

If the output from this command is getstate() = on, the VirtualCenter Server may not be communicating with the host properly. This issue must be addressed in
order to complete the shutdown process.

If the output from this command is getstate() = off, the ESX host may be unaware it is still running the virtual machine. This article provides additional
assistance in addressing this issue.
Powering off the virtual machine while collecting diagnostic information using the vm-support script

Use the following procedure when you want to investigate the cause of the issue. This command attempts to power off the virtual machine while collecting
diagnostic information. Perform these steps in order, as they are listed in order of potential impact to the system if performed incorrectly.

Perform these steps first:
1.Determine the WorldID with the command:

# vm-support -x


2.Kill the virtual machine by using the following command in the home directory of the virtual machine:

# vm-support -X

This can take upwards of 30 minutes to terminate the virtual machine.

Note: This command uses several different methods to stop the virtual machine. When attempting each method, the command waits for a pre-determined amount of
time. The timeout value can be configured to be 0 by adding -d0 to switch to the vm-support command.
If the preceding steps fail, perform the following steps for an ESX 3.x host:
1.List all running virtual machines to find the VMID of the affected virtual machine with the command:

# cat /proc/vmware/vm/*/names


2.Determine the master world ID with the command:

# less -S /proc/vmware/vm/####/cpu/status


3.Scroll to the right with the arrow keys until you see the group field. It appears similar to:

Group
vm.####


4.Run the following command to shut the virtual machine down with the group ID:

# /usr/lib/vmware/bin/vmkload_app -k 9 ####
If the preceding steps fail, perform the following steps for an ESX 4.x host:
1.List all running virtual machines to find the vmxCartelID of the affected virtual machine with the command:

# /usr/lib/vmware/bin/vmdumper -l


2.Scroll through the list until you see your virtual machine's name. The output appears similar to:

vmid=5151 pid=-1 cfgFile="/vmfs/volumes/4a16a48a-d807aa7e-e674-001e4ffc52e9/mdineeen_test/vm_test.vmx" uuid="56 4d a6 db 0a e2 e5 3e-a9 2b 31 4b 69
29 15 19" displayName="vm_test" vmxCartelID=####


3.Run the following command to shut the virtual machine down with the vmxCartelID:

# /usr/lib/vmware/bin/vmkload_app -k 9 ####
Powering off the virtual machine using the vmware-cmd command

This procedure uses the ESX command line tool, and attempts to gracefully power off the virtual machine. It works if the virtual machine's process is running
properly and is accessible. If unsuccessful, the virtual machine's process may not be running properly and may require further troubleshooting.
1.From the Service Console of the ESX host, run the following command:

vmware-cmd stop

Note: is the complete path to the configuration file, as determined in the previous section. To verify that it is stopped, run the command:

# vmware-cmd getstate


2.From the Service Console of the ESX host, run the command:

# vmware-cmd stop hard

Note: is the complete path to the configuration file, as determined in the previous section. To verify that it is stopped, run the command:

# vmware-cmd getstate


3.If the virtual machine is still inaccessible, proceed to the next section.
Using the ESX command line to kill the virtual machine

If the virtual machine does not power off using the steps in this article, it has likely lost control of its process. You need to manually kill the process
at the command line.

Caution: This procedure is potentially hazardous to the ESX host. If you do not identify the appropriate process id (PID), and kill the wrong process, it may
have unanticipated results. If you are not comfortable with the following procedure, contact VMware Technical Support and open a Service Request. Please
refer to this article when you create the SR.
1.To determine if the virtual machine process is running on the ESX host, run the command:

# ps auxwww |grep -i .vmx

The output of this command appears similar to the following if the .vmx process is running:

root 3093 0.0 0.3 2016 860 ? S< Jul30 0:17 /usr/lib/vmware/bin/vmkload_app /usr/lib/vmware/bin/vmware-vmx -ssched.group=host/user -# name=VMware ESX Server;version=3.5.0;licensename=VMware ESX Server;licenseversion=2.0 build-158874; -@ pipe=/tmp/vmhsdaemon-0/vmx569228e44baf49d1; /vmfs/volumes/49392e30- 162037d0-17c6-001f29e9abec//.vmx

The process ID (PID) for this process is in bold. In this example, the PID is 3093. Take note of this number for use in the following steps.

Caution: Ensure that you identify the line specific only to the virtual machine you are attempting to repair. If you continue this process for another
virtual machine the one in question, you can cause downtime for the other virtual machine.

If the .vmx process is listed, it is possible that the virtual machine has lost control of the process and that it must be stopped manually.


2.To kill the process, run the command:

# kill


3.Wait 30 seconds and check for the process again.
4.If it is not terminated, run the command:

# kill -9


5.Wait 30 seconds and check for the process again.
6.If it is not terminated, the ESX host may need to be rebooted to clear the process. This is a last resort option, and should only be attempted if the
preceding steps in this article are unsuccessful.


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16) Why we use two different ports for licenses, and what r those port No.?

27000 --- License transactions from ESX Server 3i to the license server (lmgrd.exe).|Outgoing TCP|

27010 --- License transactions from ESX Server 3i to the license server (vmwarelm.exe).|Outgoing TCP|

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17) VC server is not coming up, how to troubleshoot?


------------------------------------------------------------------------------------------------------------------------------
18) Difference between ESX3.5 & 4.0?


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19) Briefly describe about update Manager, is it possible to update the powered off vms by update manager?


------------------------------------------------------------------------------------------------------------------------------
20) Explain VMware Snapshot & what is d command to take a snapshot?


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21) Suppose we have 3 port groups configured in a single Vswitch (connected to single physical NIC of the esx host) with 3 different VLANs so how d VMs from
one VLAN will communicate to another VM of different VLAN?

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22) What is d command to list all the running VMs & registered VMs?

Run the vm-support -x command to show which virtual machines are currently running on the ESX host.

Run the vmware-cmd -l command to display the names of the virtual machines registered on this host.


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23) What is d command to list d HBAs?

esxcfg-scsidevs -a (-a|--hbas Print HBA devices with identifying information)

esxcfg-scsidevs -A (-A|--hba-device-list Print a mapping between HBAs and the devices it provides paths to.)

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24) What r d P2V conversion processes/tools available, how we can perform d P2V of a Linux server with d help of CLI commands (in case no specific tools
available)?

Converting a powered on Windows operating system (P2V)
Source Destination TCP Ports UDP Ports Notes

Converter server to Source computer 445, 139, 9089, 9090 137, 138 If the source computer uses NetBIOS, port 445 is not required. If NetBIOS is not being
used, ports 137, 138, and 139 are not required. If in doubt, make sure that none of the ports are blocked.
Note: Unless you have installed Converter server to the source computer, the account used for authentication to the source computer must have a password, the
source computer must have network file sharing enabled, and it cannot be using Simple File Sharing.
Converter server to VirtualCenter 443 Only required if the conversion target is VirtualCenter.
Converter client to Converter server 443 Only required if a custom installation was performed and the Converter server and client portions are on different
computers.
Source computer to ESX 443, 902 If the conversion target is VirtualCenter then only port 902 is required.

Converting a powered on Linux operating system (P2V)
Source Destination TCP Ports Notes
Converter server to Source computer 22 The Converter server must be able to establish an SSH connection with the source computer.
Converter client to Converter server 443 Only required if a custom installation was performed and the Converter server and client portions are on different
computers.
Converter server to VirtualCenter 443 Only required if the conversion target is VirtualCenter.
Converter server to ESX 443, 902, 903 If the conversion target is VirtualCenter, only ports 902 and 903 are required.
Converter server to Helper virtual machine 443
Helper virtual machine Source computer 22 The helper virtual machine must be able to establish an SSH connection with the source computer. By default the
helper virtual machine gets its IP address assigned by DHCP. If there is no DHCP server available on the network chosen for the target virtual machine you
must manually assign it an IP address.

Converting an existing virtual machine (V2V)
Source Destination TCP Ports UDP Ports Notes

Converter server to Fileshare path 445, 139 137, 138 This is only required for standalone virtual machine sources or destinations.

If the computer hosting the source or destination path uses NetBIOS, port 445 is not required. If NetBIOS is not being used, ports 137, 138, and 139 are not
required. If in doubt, make sure that none of the ports are blocked.
Converter client to Converter server 443 Only required if a custom installation was performed and the Converter server and client portions are on different
computers.
Converter server to VirtualCenter 443 Only required if the target is VirtualCenter.
Converter server to ESX 443, 902 If the conversion target is VirtualCenter, only port 902 is required.


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25) What is d command to check d status of a VM?

vmware-cmd getstate

Retrieve the list of VMs in inventory with the following command:
vmware-vim-cmd vmsvc/getallvms

[root@ESX-SRV-94 /]# vmware-vim-cmd vmsvc/getallvms
Vmid Name File Guest OS Version Annotation
160 VMVXP-1 [SAN-STORE-2] VMVXP-1/VMVXP-1.vmx winXPProGuest vmx-07
240 Ubuntu [ESX-Storage-94-2] Ubuntu/Ubuntu.vmx ubuntuGuest vmx-07


Then query each VM with their VMID:
vmware-vim-cmd vmsvc/power.getstate

For example:
vmware-vim-cmd vmsvc/power.getstate 160

[root@ESX-SRV-94 /]# vmware-vim-cmd vmsvc/power.getstate 160
Retrieved runtime info
Powered on


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26) What is d command to rescan the HBAs?

esxcfg-rescan

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27) How to find the world ID of a particular VM and what is d VMware proprietary command to kill the same?

vm-support -x
esxcli vms vm list

List all running virtual machines on the system to see the World ID of the virtual machine you want to
stop.
esxcli vms vm list

2 Stop the virtual machine by running the following command.

esxcli vms vm kill --type --world-id

The command supports three --type options. Try the types sequentially (soft before hard, hard before
force). The following types are supported through the --type option:
. soft – Gives the VMX process a chance to shut down cleanly (like kill or kill -SIGTERM)
. hard – Stops the VMX process immediately (like kill -9 or kill -SIGKILL)
. force – Stops the VMX process when other options do not work.
If all three options do not work, reboot your ESX/ESXi host to resolve the issue.

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28) what is d command to add a route in esx to communicate to different network segment?

Configure the route using the command:

#route add -net 142.121.56.0 netmask 255.255.254.0 gw 224.58.175.1 Add the following line to /etc/rc.local so that route is set on boot:


#/sbin/route add -net 142.121.56.0 netmask 255.255.254.0 gw 224.58.175.1 To ensure the route holds on reboot, create an executable file.

To create an executable file:
1.Login to the ESX host using a SSH client.
2.Change the directory to /etc/init.d .
3.Run this command to create a file called routes:

#vi routes


4.Add this code to the file:

##! /bin/bash # case "$1" in 'start') echo "Adding additional routes... "

/sbin/route add -net 172.31.3.0 netmask 255.255.255.0 gw 172.31.8.1; echo ;; *) echo "Usage: $0 { start }" ;; esac


5.Save the file and exit the vi editor.


6.Run this command to make the file executable:

#chmod 777 routes


7.Change the directory to /etc/rc3.d.
8.Run this command to create a symbolic link to that file:

#ln /etc/init.d/routes

9.Reboot the ESX host for the changes to take effect.

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29) What is d default size of the swap partition & SC MEMORY?

1600MB SWAP, 400 MB (MAX 800MB)

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30) How to increase SC memory after the esx build?



•ESX Host – 8GB RAM -> Default allocated Service Console RAM = 300MB
•ESX Host – 16GB RAM -> Default allocated Service Console RAM = 400MB
•ESX Host – 32GB RAM -> Default allocated Service Console RAM = 500MB
•ESX Host – 64GB RAM -> Default allocated Service Console RAM = 602MB
•ESX Host – 96GB RAM -> Default allocated Service Console RAM = 661MB
•ESX Host – 128GB RAM -> Default allocated Service Console RAM = 703MB
•ESX Host – 256GB RAM -> Default allocated Service Console RAM = 800MB

cp /etc/vmware/esx.conf /etc/vmware/esx.conf.old
cp /boot/grub/grub.conf /boot/grub/grub.conf.old
/bin/sed -i -e ‘s/272/800/’ /etc/vmware/esx.conf
/bin/sed -i -e ‘s/512/800/’ /etc/vmware/esx.conf
/bin/sed -i -e ‘s/272M/800M/’ /boot/grub/grub.conf
/bin/sed -i -e ‘s/512M/800M/’ /boot/grub/grub.conf
/bin/sed -i -e ‘s/277504/818176/’ /boot/grub/grub.conf
/bin/sed -i -e ‘s/523264/818176/’ /boot/grub/grub.conf

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31) What r d port No. for Vmotion & VMware converter?

ESX 4.x 8000 TCP ESX/ESXi Host (VM Target) TO ESX/ESXi Host (VM Source) VMotion Communication on VMKernel Interface
ESX 4.x 8000 TCP ESX/ESXi Host (VM Source) TO ESX/ESXi Host (VM Target) VMotion Communication on VMKernel Interface

ESXi 4.x 8000 TCP ESX/ESXi Host (VM Target) TO ESX/ESXi Host (VM Source) VMotion Communication on VMkernel Interface
ESXi 4.x 8000 TCP ESX/ESXi Host (VM Source) TO ESX/ESXi Host (VM Target) VMotion Communication on VMkernel Interface

Converter 4.x 22 TCP Helper Virtual Machine Source Computer to be converted Required for conversion of Linux-based source computers (data flows from source
to VM)

Converter 4.x 22 TCP vCenter Converter Server Source Computer to be converted Required for conversion of Linux-based source computers

Converter 4.x 137 UDP vCenter Converter Server Source Computer to be converted For hot migration. Not required if the source computer does not use NetBIOS

Converter 4.x 138 UDP vCenter Converter Server Source Computer to be converted For hot migration. Not required if the source computer does not use NetBIOS

Converter 4.x 139 TCP vCenter Converter Server Source Computer to be converted For hot migration. Not required if the source computer does not use NetBIOS

Converter 4.x 443 TCP vCenter Converter Client vCenter Converter Server Only required if the Converter Client and Converter Server were installed on
different systems

Converter 4.x 443 TCP Source Computer to be converted ESX/ESXi Host Required for destination VM access when target is ESX/ESXi/vCenter

Converter 4.x 443 TCP Source Computer to be converted vCenter Server Required if vCenter Server is the conversion target

Converter 4.x 443 TCP vCenter Converter Server vCenter Server Required if vCenter Server is the conversion target

Converter 4.x 443 TCP vCenter Converter Server ESX/ESXi Host Required for system conversion

Converter 4.x 443 TCP vCenter Converter Server Helper Virtual Machine Required for conversion of Linux-based source computers

Converter 4.x 445 TCP vCenter Converter Server Source Computer to be converted Required for system conversion. Not required if the source computer uses
NetBIOS

Converter 4.x 902 TCP Source Computer to be converted ESX/ESXi Host Required for data transport during cloning of system to be converted to target ESX/ESXi
Host

Converter 4.x 9089, 9090 TCP vCenter Converter Server Source Computer to be converted Required for system conversion. Remote agent deployment

------------------------------------------------------------------------------------------------------------------------------
32) How to create Vmkcore partition after the esx build?

using parted we can create vmkcore partition if there is free space availabe else first free up about 100MB space on disk by resizing the root or any other
partion on the disk and then create new vmkcore partion with fc filesystem and reboot the host.


------------------------------------------------------------------------------------------------------------------------------
33) What r d agents will install, after adding an esx in VC server?

Vmware vcenter Agent


----------------------------------------------------------------------------------------------------------
34) What r d port No. for VMware management service?

8080, 8443 VMware vCenter 4 Management Web Services - HTTP and HTTPS


----------------------------------------------------------------------------------------------------------
35) What is d max No of VMs can run per host?

320

----------------------------------------------------------------------------------------------------------
36) What r all d files going to b create after a vm build?

.vmx, .vmfx, .vmsd, .vmdk (when start 3 more files are created --- .log, vswp, .nvram)

----------------------------------------------------------------------------------------------------------
37) What r d location of VC server log files?

C:\ProgramData\VMware\VMware VirtualCenter\Logs

---------------------------------------------------------------------------------------------------------
38) What r d necessary log files in ESX server?

esx server logs

VMWare ESX Server Logs

1) Vmkernel

a. Location: /var/log/

b. Filename: vmkernel

c. This log records information related to the vmkernel and virtual machines

2) Vmkernel Warnings

a. Location: /var/log/

b. Filename: vmkwarning

c. This log records information regarding virtual machine warnings

3) Vmkernel Summary

a. Location: /var/log/

b. Filename: vmksummary

c. This log records information used to determine uptime and availability statistics for ESX Server. This log is not easily readable by humans, import
into a spreadsheet or database for use.

d. For a summary of the statistics in an easily viewed file, see vmksummary.txt

4) ESX Server Boot Log

a. Location: /var/log

b. Filename: boot.log

c. Log file of all actions that occurred during the ESX server boot.

5) ESX Server Host Aagent Log

a. Location: /var/log/vmware/

b. Filename: hostd.log

c. Contains information on the agent that manages and configures the ESX Server host and its virtual machines (Search the file date/time stamps to find
the log file it is currently outputting to).

6) Service Console

a. Location: /var/log/

b. Filename: messages

c. Contain all general log messages used to troubleshoot virtual machines on ESX Server.

7) Web Access

a. Location: /var/log/vmware/webAccess

b. Filename: various files in this location

c. Various logs on Web access to the ESX Server.

8) Authentication Log

a. Location: /var/log/

b. Filename: secure

c. Contains the records of connections that require authentication, such as VMware daemons and actions initiated by the xinetd daemon.

9) VirtualCenter HA Agent Log

a. Location: /var/log/vmware/aam/

b. Filename: aam_config_util_*.log

c. These files contain information about the installation, configuration, and connections to other HA agents in the cluster.

10) VirtualCenter Agent

a. Location: /var/log/vmware/vpx

b. Filename: vpxa.log

c. Contains information on the agent that communicates with the VirtualCenter Server.

11) Virtual Machine Logs

a. Location: The same directory as the virtual machine’s configuration files are placed in.

b. FileName: vmware.log

c. Contains information when a virtual machine crashes or ends abnormally.



VirtualCenter Installation Logs

1) The following install logs are located in the %TEMP% directory of the user that installed VirtualCenter

a. vmlic.log i. Contains various test results for provided license file during the installation.

b. redist.log i. Contains MDAC/MCAD QFE rollup installation information

c. vmmsde.log i. Contains MSDE installation information

d. vmls.log i. The License server installation log.

e. vmosql.log i. The VirtualCenter database creation log file

f. vminst.log i. VirtualCenter installation log file

g. VCDatabaseUpgrade.log i. Results on upgrading the VC Database.

h. vmmsi.log i. The VI client installation log. Vpxd-0.log is a small log from the starting the client the first time.

Virtual Center Logs

1) Location:

a. C:\Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter\Logs

2) Name: vpxd-#.log (# is one digit, 0-9)

a. vpxd-index contains the # of the currently active log file

3) Logs rotate each time vpxd is started, and also when it reaches 5 MB in size

VI Client Logs

1) Location: User %TEMP%\vpx

2) Name: viclient-#.log (# is one digit, 0-9)

3) Logs rotate each time VI Client is started, and is should be used for client-specific diagnostics

Miscellaneous Logs

1) Core Dump

a. Location: %USERPROFILE%\Application Data\VMware

2) License Server Debug Log

a. Location: %SystemRoot%\Temp

b. Filename: lmgrd.log i. This file is overwritten each time the service starts

c. This file contains various information about the license file and server.

3) Web Access (Tomcat) Logs

a. Location: C:\Program Files\VMware\Infrastructure\VirtualCenter Server\tomcat\logs

b. Filename: various files

c. All the Tomcat logs are here


esx-console logs
sysboot-vmkernel-boot.log , sysboot-dmesg-boot.log, sysboot-vmkernel-late.log, sysboot-dmesg-late.og, sysboot.log

cd /vmfs/volumes/ESX-Storage-94-1/esxconsole-4c44398f-4238-b888-226e-001e0bcd236a/logs/

Core-dump location

cd vmfs/volumes/ESX-Storage-94-1/esxconsole-4c44398f-4238-b888-226e-001e0bcd236a/core-dumps


----------------------------------------------------------------------------------------------------------------------
39) What is ESXTOP command and how to use this command (with all the fields/options)?

Esxtop version 4.1.0
Secure mode Off

Esxtop: top for ESX

These single-character commands are available:

^L - redraw screen
space - update display
h or ? - help; show this text
q - quit

Interactive commands are:

fF Add or remove fields
oO Change the order of displayed fields
s Set the delay in seconds between updates
# Set the number of instances to display
W Write configuration file ~/.esxtop41rc
k Kill a world
e Expand/Rollup Cpu Statistics
V View only VM instances
L Change the length of the NAME field
l Limit display to a single group

Sort by:
U:%USED R:%RDY N:GID
Switch display:
c:cpu i:interrupt m:memory n:network
d:disk adapter u:disk device v:disk VM p:power mgmt

Hit any key to continue:


9:26:17pm up 9 days 45 min, 149 worlds; CPU load average: 0.02, 0.06, 0.06
PCPU USED(%): 2.5 32 38 0.3 19 0.5 0.3 0.4 2.2 57 0.0 0.0 0.3 24 0.3 50 AVG: 14
PCPU UTIL(%): 3.4 34 41 0.5 26 1.0 0.7 0.7 2.7 65 0.2 0.2 0.6 29 0.6 60 AVG: 16
CCPU(%): 0 us, 2 sy, 97 id, 0 wa ; cs/sec: 108

ID GID NAME NWLD %USED %RUN %SYS %WAIT %RDY %IDLE %OVRLP %CSTP %MLMTD %SWPWT
1 1 idle 16 1351.56 1497.67 0.00 0.00 122.22 0.00 0.94 0.00 0.00 0.00
59 59 Ubuntu 7 229.64 264.45 0.00 441.37 0.02 138.50 0.79 0.00 0.00 0.00
11 11 console 1 1.65 2.66 0.03 98.24 0.07 98.23 0.01 0.00 0.00 0.00
60 60 VMVXP-1 5 1.08 1.56 0.00 500.00 0.10 199.79 0.01 0.00 0.00 0.00
7 7 helper 77 0.04 0.05 0.00 7700.00 0.01 0.00 0.00 0.00 0.00 0.00
8 8 drivers 10 0.01 0.01 0.00 1000.00 0.00 0.00 0.00 0.00 0.00 0.00
56 56 vmkiscsid.4303 2 0.01 0.01 0.00 200.00 0.00 0.00 0.00 0.00 0.00 0.00
49 49 storageRM.4292 1 0.00 0.00 0.00 100.00 0.00 0.00 0.00 0.00 0.00 0.00
19 19 vmkapimod 9 0.00 0.00 0.00 900.00 0.00 0.00 0.00 0.00 0.00 0.00
2 2 system 7 0.00 0.00 0.00 700.00 0.00 0.00 0.00 0.00 0.00 0.00
9 9 vmotion 4 0.00 0.00 0.00 400.00 0.00 0.00 0.00 0.00 0.00 0.00
47 47 FT 1 0.00 0.00 0.00 100.00 0.00 0.00 0.00 0.00 0.00 0.00
48 48 vobd.4291 6 0.00 0.00 0.00 600.00 0.00 0.00 0.00 0.00 0.00 0.00
52 52 net-cdp.4300 1 0.00 0.00 0.00 100.00 0.00 0.00 0.00 0.00 0.00 0.00
53 53 net-lbt.4301 1 0.00 0.00 0.00 100.00 0.00 0.00 0.00 0.00 0.00 0.00
57 57 vmware-vmkauthd 1 0.00 0.00 0.00 100.00 0.00 0.00 0.00 0.00 0.00 0.00

The following optional switches, relevant to esxtop in batch mode, can be used:

a Shows all statistics and not what is specified in the default configuration file, if it exists.
b Runs esxtop in batch mode.
c Loads a user-defined configuration file instead of the ~/.esxtop310rc default.
d Specifies the delay between statistics updates; the default is 5 seconds and the minimum is 2.
n Specified the number of statistics updates to capture before exiting.

For example, the following command would run esxtop in batch mode, updating all statistics to the file perfstats.csv every 10 seconds for 360 iterations (a
total of 60 minutes) before exiting:

esxtop -a -b -d 10 -n 360 > perfstats.csv

-------------------------------------------------------------------------------------------------
40) What is d location of esx dump file and how to read it?

Core-dump location

cd vmfs/volumes/ESX-Storage-94-1/esxconsole-4c44398f-4238-b888-226e-001e0bcd236a/core-dumps
-----------------------------------------------------------------------------------------------------
41) What id d location of the license file (*.LIC) in VC server and ESX server?

C:\ProgramData\VMware\VMware VirtualCenter\licenses\site\VMware VirtualCenter Server\4.0\4.1.0.2


----------------------------------------------------------------------------------------------------
42) What is d command to check the VMFS version and ESX version?

vmkfstools -P storageN
vmware -v and
vimsh -n -e 'hostsvc/hostsummary' | grep fullName OR
cat /proc/vmware/version

-----------------------------------------------------------------------------------------------------------
43) How to extend the OS drive of a guest OS (windows VM)

vmkfstools -X 50M /vmfs/volumes/Storage2/testvm/testvm.vmdk

vmkfstools -X 50M /vmfs/volumes/Storage2/testvm/testvm.vmdk

----------------------------------------------------------------------------------------------------------
44) What is d command to clone a VM?

vmware-vdiskmanager with option -r

# vmkfstools -i /vmfs/volumes/Datastore04/rhel5_test_template/rhel5_test_template.vmdk /vmfs/volumes/Datastore04/rhel5_test_clone/rhel5_test_clone.vmdk

-----------------------------------------------------------------------------------------------------------
45) What is d command to check all d virtual switch configuration details?

To configure networking from the ESX service console command line:
1.Ensure the network adapter you want to use is currently connected with the command:

[root@server root]# esxcfg-nics –l

The output appears similar to:

Name PCI Driver Link Speed Duplex Description
vmnic0 06:00.00 tg3 Up 1000Mbps Full Broadcom Corporation NetXtreme BCM5721 Gigabit Ethernet
vmnic1 07:00.00 tg3 Up 1000Mbps Full Broadcom Corporation NetXtreme BCM5721 Gigabit Ethernet

In the Link column, Up indicates that the network adapter is available and functioning.
2.List the current virtual switches with the command:

[root@server root]# esxcfg-vswitch –l

The output appears similar to:

Switch Name Num Ports Used Ports Configured Ports Uplinks
vSwitch0 32 3 32 vmnic0

PortGroup Name Internal ID VLAN ID Used Ports Uplinks
VM Network portgroup2 0 0 vmnic0

In the example output, there exists a virtual machine network named VM Network with no Service Console portgroup. For illustration, the proceeding steps show
you how to create a new virtual switch and place the service console port group on it.


3.Create a new virtual switch with the command:

[root@server root]# esxcfg-vswitch –a vSwitch1


4.Create the Service Console portgroup on this new virtual switch:

[root@server root]# esxcfg-vswitch –A “Service Console” vSwitch1

Because there is a space in the name (Service Console), you must enclose it in quotation marks.

Note: To create Service Consoles one at time, you may need to delete all previous settings. For more information, see Recreating Service Console Networking
from the command line (1000266).


5.Up-link vmnic1 to the new virtual switch with the command:

[root@server root]# esxcfg-vswitch –L vmnic1 vSwitch1


6.If you need to assign a VLAN, use the command:

[root@server root]# esxcfg-vswitch -v -p “Service Console” vSwitch0

where is the VLAN number. A zero here specifies no VLAN.


7.Verify the new virtual switch configuration with the command:

[root@server root]# esxcfg-vswitch –l

The output appears similar to:

Switch Name Num Ports Used Ports Configured Ports Uplinks
vSwitch0 32 3 32 vmnic0

PortGroup Name Internal ID VLAN ID Used Ports Uplinks
Service Console portgroup5 0 1 vmnic0

Switch Name Num Ports Used Ports Configured Ports Uplinks
vSwitch1 64 1 64 vmnic1

PortGroup Name Internal ID VLAN ID Used Ports Uplinks
Service Console portgroup14 0 1 vmnic1


8.Create the vswif (Service Console) interface. For example, run the command:

[root@server root]# esxcfg-vswif –a vswif0 –i 192.168.1.10 –n 255.255.255.0 –p “Service Console”
[‘Vnic’ warning] Generated New Mac address, 00:50:xx:xx:xx:xx for vswif0

Nothing to flush.


9.Verify the configuration with the command:

[root@esx]# esxcfg-vswif –l
Name Port Group IP Address Netmask Broadcast Enabled DHCP
v swif0 Service Console 192.168.1.10 255.255.255.0 192.168.1.255 true false



----------------------------------------------------------------------------------------------------------------------------------------------
46) What is d command to upgrade the FS fromVMFS2 to VMFS3?

The first thing that you will need to do to perform the upgrade is log into the ESX 3 host as root. Once logged in then you need to unload the ESX 3 VMFS
drivers that are currently loaded. The unloading of the VMFS drivers is for both VMFS 2 and VMFS 3. To perform this you need to run the commands below.

vmkload_mod -u vmfs2

vmkload_mod -u vmfs3

You then need to load a specific driver for ESX3 that is called the "ESX3 Auxiliary FS driver". The command below that loads this driver also includes the
switch to enable the upgrade mode contained within the driver.

vmkload_mod fsaux fsauxFunction=upgrade

The next step is to perform the upgrade on the VMFS2 volume. To do this, you need to make sure that there are no other hosts accessing the volume. This is
very important, as it will go pear shaped quickly if other servers try to access the volume during the upgrade process.

vmkfstools -T /vmfs/volumes/

Once the upgrade is completed, you need to check and confirm that the volume is vmfs3. You can do this by running the following command which is once again
another vmkfstools command.

vmkfstools -P /vmfs/volumes/

You should also confirm that all your files are ok by checking the file system. The commonly used list command for file systems at the service console is "ls
-l". If you have any more volumes to upgrade you may rinse and repeat the steps above until they are all done. Once all your volumes are upgraded you do
need to unload the "auxiliary driver" that we loaded before and reload the normal VMFS drivers. Two ways of doing this, one is to reboot and the other is to
run the commands below.

vmkload_mod -u fsaux

vmkload_mod vmfs2

vmkload_mod vmfs3

•ESX 3.0.0 is provided with 3.21 (initial release)
•ESX 3.5.0 is provided with 3.31
•vSphere (ESX 4.0) is provided with 3.33
•vSphere (ESX 4.1) is provided with 3.46



-------------------------------------------------------------------------------------------------------------------------------
47) What is RDM and what r all d File Systems (FS) it supports?



-------------------------------------------------------------------------------------------------------------------------------
48) What is SRM and how it works?

VMware vCenter Site Recovery Manager delivers advanced capabilities for disaster recovery management, non-disruptive testing and automated failover. VMware
vCenter Site Recovery Manager can manage failover from production datacenters to disaster recovery sites, as well as failover between two sites with active
workloads. Multiple sites can even recover into a single shared recovery site. Site Recovery Manager can also help with planned datacenter failovers such as
datacenter migrations.

Disaster Recovery Management

. Create and manage recovery plans directly from VMware vCenter Server.
. Discover and display virtual machines protected by storage replication using integrations certified by storage vendors.
. Extend recovery plans with custom scripts.
. Monitor availability of remote site and alert users of possible site failures.
. Store, view and export results of test and failover execution from VMware vCenter Server.
. Control access to recovery plans with granular role-based access controls.
. Leverage iSCSI, FibreChannel, or NFS-based storage replication solutions.
. Recover multiple sites into a single shared recovery site.
. Take advantage of the latest features and technologies included in VMware vSphere.

Non-Disruptive Testing

. Use storage snapshot capabilities to perform recovery tests without losing replicated data.
. Connect virtual machines to an existing isolated network for testing purposes.
. Automate execution of tests of recovery plans.
. Customize execution of recovery plans for testing scenarios.
. Automate cleanup of testing environments after completing tests.

Automated Failover

. Initiate recovery plan execution from VMware vCenter Server with a single button.
. Automate promotion of replicated datastores for recovery using adapters created by leading storage vendors for their replication platforms.
. Execute user-defined scripts and pauses during recovery.
. Reconfigure virtual machines’ IP addresses to match network configuration at failover site.
. Manage and monitor execution of recovery plans within VMware vCenter Server.

What’s New in vCenter Site Recovery Manager 4?

. Protect more of your environment with added support for NFS storage replication.
. Set up many-to-one failover using shared recovery sites.
. Leverage new features in vSphere.


-------------------------------------------------------------------------------------------------------------------------------
49) What is d series of H/W (virtual) used for VM’s virtual mother mother/main board?



-------------------------------------------------------------------------------------------------------------------------------
50) What r d date store path selections & what r d options available for network load balancing?

You can display information about paths by running vicfg-mpath with one of the following options:
. List all devices with their corresponding paths, state of the path, adapter type, and other information.
vicfg-mpath --list-paths
. Display a short listing of all paths.
vicfg-mpath --list-compact
. List all paths with adapter and device mappings.
vicfg-mpath --list-map

Managing Path Policies with esxcli

For each storage device managed by NMP (not PowerPath), an ESX/ESXi host uses a path selection policy. By
default, VMware supports the following path selection policies. If you have a third‐party PSP installed on your
host, its policy also appears on the list. The following path policies are supported by default:

Table 5-1. Supported Path Policies

Policy Description

VMW_PSP_FIXED The host always uses the preferred path to the disk when that path is available. If the host
cannot access the disk through the preferred path, it tries the alternative paths. If you use the

VMW_PSP_FIXED policy, use esxcli nmp fixed to set or get the preferred path

VMW_PSP_FIXED_AP Extends the VMW_PSP_FIXED functionality to active‐passive and ALUA mode arrays.

VMW_PSP_MRU The host uses a path to the disk until the path becomes unavailable. When the path becomes
unavailable, the host selects one of the alternative paths. The host does not revert back to the
original path when that path becomes available again. There is no preferred path setting with
the MRU policy. MRU is the default policy for active‐passive storage devices and is required
for those devices.

VMW_PSP_RR The host uses an automatic path selection algorithm rotating through all available paths. This
algorithm implements load balancing across all the available physical paths. Load balancing
is the process of spreading server I/O requests across all available host paths. The goal is to
optimize performance in terms of throughput (I/O per second, megabytes per second, or
response times).

Table 5-2. Path Policy Effects

Policy Active/Active Array Active/Passive Array
Most Recently Used Administrator action is required to fail
back after path failure.
Administrator action is required to fail back
after path failure.
Fixed VMkernel resumes using the preferred
path when connectivity is restored.
VMkernel attempts to resume using the
preferred path. This can cause path
thrashing or failure when another SP now
owns the LUN.
Round Robin No fail back. Next path in round robin scheduling is
selected.
VMWare Top Interview Questions with Answers

1) Explain about your production environment? How many cluster’s, ESX, Data Centers, H/w etc ?
2) How does VMotion works? What’s the port number used for it?
ANS--> TCP port 8000

3) Prerequisites for VMotion?
Ans-->
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NAS/NFS
6)The VMs can not use localcd/floppy or internal only vrtual switches on the ESX server

Check out http://www.vmware.com/pdf/vi3_35/esx_3/r35u2/vi3_35_25_u2_admin_guide.pdf for more information

4) How does HA works? Port number? How many host failure allowed and why?
ANS--> Maximum allowed host failures within a HA cluster is 4. What happens if 4 hosts have failed and a 5th one also fails.
I have still enough free resources to start up the virtual machines on the remaining hosts. Will HA start these virtual machines from the 5th failed host on the remaining hosts?
ANS) That depends. If you have admission control enabled, if there are any resource constraints some VM's may not restart. If you have admission control disabled, the VM's will get restarted on any host left in the cluster. However, that doesn't mean they will be functional. Make sure you have enough port groups configured on your vSwitch for your Virtual Machine port group to accommodate

Host Firewalls. On ESX/ESXi hosts, VMware HA needs and automatically opens the following firewall ports.
Incoming port: TCP/UDP 8042-8045
Outgoing port: TCP/UDP 2050-2250

5) What are active host / primary host in HA? Explain it?
ANS-->
When you add a host to a VMware HA cluster, an agent is uploaded to the host and configured to communicate
with other agents in the cluster. The first five hosts added to the cluster are designated as primary hosts, and
all subsequent hosts are designated as secondary hosts. The primary hosts maintain and replicate all cluster
state and are used to initiate failover actions. If a primary host is removed from the cluster, VMware HA
promotes another host to primary status.
Any host that joins the cluster must communicate with an existing primary host to complete its configuration
(except when you are adding the first host to the cluster). At least one primary host must be functional for
VMware HA to operate correctly. If all primary hosts are unavailable (not responding), no hosts can be
successfully configured for VMware HA.

One of the primary hosts is also designated as the active primary host and its responsibilities include:
n Deciding where to restart virtual machines.
n Keeping track of failed restart attempts.
n Determining when it is appropriate to keep trying to restart a virtual machine.
If the active primary host fails, another primary host replaces it.

6) Prerequisites for HA ?
First, for clusters enabled for VMware HA, all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN, iSCSI SAN, or SAN iSCI NAS), because you need to
be able to power on the virtual machine on any host in the cluster.
Second, VMware HA monitors heartbeat between hosts on the console network for failure
detection. So, to have reliable failure detection for HA clusters, the console network should have
redundant network paths. That way, if a host's first network connection fails, the second
connection can broadcast heartbeats to other hosts.
Last, if you want to use DRS with HA for load balancing, the hosts in your cluster must be part of
a VMotion network. If the hosts are not in the VMotion network, however, DRS can still make
initial placement recommendations.

7) How do DRS works? Which technology used? What are the priority counts to migrate the VM’s?
8) How does snap shot’s works?
9) What are the files will be created while creating a VM and after powering on the VM?
10) If the VMDK header file corrupt what will happen? How do you troubleshoot?
11) Prerequisites VC, Update manager?
12) Have you ever patched the ESX host? What are the steps involved in that?
13) Have you ever installed an ESX host? What are the pre and post conversion steps involved in that? What would be the portions listed? What would be the max size of it?
14) I turned on Maintenance mode in an ESX host, all the VM’s has been migrated to another host, but only one VM failed to migrate? What are the possible reasons?
15) How will you turn start / stop a VM through command prompt?
16) I have upgraded a VM from 4 to 8 GB RAM; it’s getting failed at 90% of powering on? How do you troubleshoot?
17) Storage team provided the new LUN ID to you? How will you configure the LUN in VC? What would be the block size (say for 500 GB volume size)?
18) I want to add a new VLAN to the production network? What are the steps involved in that? And how do you enable it?
19) Explain about VCB? What it the minimum priority (*) to consolidate a machine?
20) How VDR works?
21) What’s the difference between Top and ESXTOP command?
22) How will you check the network bandwidth utilization in an ESXS host through command prompt?
23) How will you generate a report for list of ESX, VM’s, RAM and CPU used in your Vsphere environment?
24) What the difference between connecting the ESX host through VC and Vsphere? What are the services involved in that? What are the port numbers’s used?
25) How does FT works? Prerequisites? Port used?
26) Can I VMotion between 2 different data centers? Why?
27) Can I deploy a VM by template in different data centers ?
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM? How will you do it without any interruption to the end user?
29) Which port number used while 2 ESX transfer the data in between?
30) Unable to connect to a VC through Vsphere client? What could be the reason? How do you troubleshoot?
31) Have you ever upgraded the ESX 3.5 to 4.0? How did you do it?
32) What are the Vsphere 4.0, VC 4.0, ESX 4.0, VM 7.0 special features?
33) What is AAM? Where is it used? How do you start or stop through command prompt?
ANS) VMware-aam = HA.
VMware purchased the HA technology from Legato, who originally coined it as "Automated Availability Manager".

34) Have you ever called VMWare support? Etc

35) Explain about Vsphere Licensing? License server?

36) How will you change the service console IP?
Note: ESX 4.0 Update 2 introduces a new tool that simplifies the process of creating or restoring networking in the ESX service console. For more information, see Configuring or restoring networking from the ESX service console using console-setup (1022078).

Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a remote console session. If you make changes through a network connection such as SSH, network connectivity to the Service Console disconnects because the Service Console's network interface changes.

1.Run this command to set the IP address:

[root@server root]# esxcfg-vswif -i -n vswif0

where is the IP address and is the subnet mask.

Note: In this example, vswif0 is the Service Console adapter that is the interface to which you are applying the IP address change.


2.Open the /etc/hosts file with a text editor and modify it so that it reflects the correct IP address and hostname.
3.To change the default gateway address and the hostname, edit the /etc/sysconfig/network file and change the GATEWAY and HOSTNAME parameters to the proper values.
4.For the changes to take place, restart the network service with the command:

[root@server root]# service network restart

Note: If you are required to edit the hostname, then you must reboot the host.

Note: This command breaks any current network connections to the Service Console, but virtual machines continue to have network connection. If the ESX host is managed by VirtualCenter or vCenter Server, you may have to remove and re-add the host to the inventory. For more information, see ESX not working properly in VirtualCenter after IP address change (1005633).
Note: Making changes to IP and DNS server settings can have a negative impact on the normal operation of ESX/ESXi, particularly in HA clustered environments. For more information, see Identifying issues with and setting up name resolution on ESX/ESXi Server (1003735).

Note: If the changed IP does not persist across a reboot, try deleting and recreating the Service Console vswif management interface. For more information, see Recreating Service Console networking from the command line (1000266).
Changing the hostname without rebooting
To dynamically change the hostname, run the command:

[root@server root]# hostname newname

Note: This command creates a temporary hostname change. This change is lost when the system is rebooted.

Changing the DNS server settings
To change the DNS server settings, update the nameserver IPs and search domain in the /etc/resolv.conf file.

Changing settings in VMware vSphere or Infrastructure Client
To change the hostname, domain, DNS servers, and default gateway in VMware vSphere or Infrastructure Client:

1.Highlight the ESX host and click the Configuration tab.
2.Click DNS and Routing.
3.Click Properties.
4.To change the hostname, domain, and DNS servers, click the DNS Configuration tab and enter the appropriate values.

Note: Disable VMware High Availability if you do not want virtual machines to failover during the hostname IP change.

5.To change the default gateway, click the Routing tab and enter the appropriate value.
6.Reboot the ESX host for the changes to take effect .
7.Reconnect the ESX host to vCenter Server with the new IP address.
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started. Under certain circumstances, it might be required to force the host to generate new certificates. Typically new certificates only need to be generated if the hostname has been changed or the certificates have been deleted accidentally.

Each time you restart the vmware-hostd process, the mgmt-vmware script searches for existing certificate files ( rui.crt and rui.key). If the files cannot be found, new certificate files are generated.

To generate new certificates:

1.Put the host into Maintenance Mode.
2.In the directory /etc/vmware/ssl, back up any existing certificates by renaming them with these commands:

[root@server root]# mv /etc/vmware/ssl/rui.crt /etc/vmware/ssl/orig.rui.crt
[root@server root]# mv /etc/vmware/ssl/rui.key /etc/vmware/ssl/orig.rui.key

Note: If you are regenerating certificates because you accidentally deleted them, you do not have to rename them.

3.Reboot your host to allow it to begin using the new certificate, or restart the host services:

a.Restart hostd, using this command:

service mgmt-vmware restart

b.Restart vmkauthd, using this command:

service vmware-vmkauthd restart

4.Exit Maintenance Mode.
5.Confirm that the ESX host successfully generated new certificates by running this command and comparing the time stamps of the new certificate files with orig.rui.crt and orig.rui.key:

[root@server root]# ls -la /etc/vmware/ssl/rui*
Notes:

•Disable VMware High Availability if you do not want virtual machines to failover during the hostname IP change. If you are using vSphere 4.x you can just disable host monitoring in the HA settings.
•For related information, see Verifying ESX Server host networking configuration on the service console (1003796).
•You may be required to regenerate your SSL certificate. For more information, see Replacing or Regenerating an SSL Certificate for the Management Interface (1843).
•You are required to edit files on an ESX host. For more information, see Editing files on an ESX host using vi or nano (1020302).
•For information on replacing VirtualCenter Server ceritificates, see:
?Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
?Replacing VirtualCenter Server Certificates in vSphere 4
•The iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the ESX host. If you change the hostname of the ESX host, ensure to review your iSCSI software initiator configuration. For more information on iSCSI troubleshooting, see Configuring and troubleshooting basic software iSCSI setup (1008083).
•For more information on changing the hostname, see Changing the name of an ESX host (1010821).

37) What’s the difference between ESX and ESXi?
38) What’s the difference between ESX 3.5 and ESX 4.0?

39) P2V Prt Number and Log file location?
TCP/IP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process.
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905, you will have to make
adjustments accordingly.
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3.x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3.x | 902
Log File Locations:
UFAD logs:
%WINDIR%\Temp\vmware-temp\vmware-converter*
%WINDIR%\vmware-temp\vmware-converter* (in Windows NT)
Client logs:
%TEMP%\vmware-temp\vmware-client*

Send these in to support using File > Export Logs. For Converter Boot CD, map a network drive using the
network configuration tool (see Chapter 5, “Using the Converter Boot CD for Local Cold Cloning,” on page 37)
and use File > Export Logs.

40) Micro vMotion
41)
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Q: How is VMware more stable than, say, a new physical server?

A: The idealized hardware provided by VMware provides a consistent virtual hardware environment that increases that stability of your virtual machines independent of the underlying physical hardware.


Q: Is any installation method better than any other?

A: No. Whichever installation method you're comfortable with and that produces a good build is the one for you.

Q: I'm having problems with my installation. What should I do?

A: Ensure that the hardware you're loading ESX Server on is supported. The same goes for the configuration. If you are certain the hardware and configuration are supported, then run the vm-support script mentioned previously.

Q: Why does this chapter include only the graphical installer method?

A: It's the recommended installation method from VMware and one that many in the x86-world are the most comfortable with. If you wish to try it another way, VMware offers a very complete installation document covering the various installation methodologies.
Q: When I copy my virtual machine and try to run it on my network, I get hostname already exists and IP address already exists errors. I thought I could simply copy my virtual machine. What is the problem?

A: You can copy your virtual machine, which is why you're running into this problem. The copy is an exact copy. Thus, you need to change the hostname, IP address, and even the computer's SID (if it has one).

Q: Can I move my Gold Master to my other ESX Servers?

A: Yes, it's a recommended time-saver. If your ESX Servers share a LUN, that too is a way to access your Gold Master or your VMlibrary for that matter.

Q: Are there any limitations to the number of virtual machines I can run on my ESX Server?

A: Yes. Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines.

Q: Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX?

A: It depends. The process is not as simple as cutting and pasting. There is a specific import process required for migrating virtual machines from either Workstation or GSX into ESX. Access the following link for the exact instructions: http://www.vmware.com/pdf/mobility_guide.pdf.
Q: Do you need to tweak the settings of your virtual machines after you've built them?

A: No. VMware has configured the defaults of your build to suit most server loads. However, depending on the profile of your server and the resource intensiveness of the service it's providing, you may want to consider tweaking some of the default settings to better ensure service stability and reliability.

Q: Are there more advanced features than the ones detailed in this chapter?

A: Yes… a lot more.

Q: Is clustering more stable in VMware?

A: We find that the idealized hardware, in combination with VMware's improvements in clustering support, has made virtual clustering very stable.

Q: Can you Vmotion a cluster?

A: That depends on the cluster type and how it is configured. Clusters using Raw Device Mapping in virtual mode can be moved with Vmotion according to VMware documentation.
Q: Does VMware support NIC teaming?

A: Yes, and it's a very good idea to configure your ESX Server, especially if it's for production, with teamed NICs. This will provide hardware fault tolerance in case one NIC fails.

Q: How many physical NICs do I need on my ESX Server?

A: That depends on the number of virtual machines and the network traffic they produce. You should have a minimum of two: one for your Service Console and one dedicated to your virtual machines.

Q: If I'm building a cluster using Microsoft Clustering Service, what's the best configuration for my heartbeat NIC?

A:For a Cluster in a Box, create a VMnet that your nodes of your cluster can attach their heartbeat NICs.

Q: Can you attach virtual machines on any ESX Server to a VMnet?

A: No. Only virtual machines on the ESX Server that the VMnet resides can attach to it.
Q: Why should you pay for a p-to-v toll when there are a number of ways to do it for free?

A: If you don't have the time or inclination to learn the manual process or need the assurance of a vendor for your physical-to-virtual migrations, then a tool that comes with support is a very reasonable option.

Q: What takes the longest in the p-to-v process?

A: Transferring the data of the physical server into either an image file or the virtual server itself. That's why tweaking your network settings for optimal throughput is essential when p-to-v'ing a server.

Q: Can you create complete backups of your physical servers and then recover them into virtuals?

A: I've used NTBackup to back up Windows 2000 Professional and Windows XP, and created virtuals out of .bkf files. It works but there's a bit of futzing around with the virtual once it is running. Try it.

Q: What's the most essential part of creating a smooth migration plan?

A: Practice. No matter what the tool or process, practice it and learn its gotchas and the workarounds. No matter what method you use, there will be times when it won't go as planned. Practicing your p-to-v process on a number of physical platforms and disk configurations allows you to become more adept once you're doing it for real.
Q: Will my software vendor support my application in a VMware environment?

A: You'll need to contact your specific software or applications vendor to find out; however, an increasing number of software vendors support virtualized environments. Once you've migrated your application from a physical to virtual environment it's very easy to migrate back to a physical environment for vendor support. An excellent document provided by VMware can be found at the following link: www.vmware.com/pdf/ms_support_statement.pdf.

Q: What are the best enablers to help ensure our server consolidation is a success?

A: Engaging with the lines of business and application owners not only assists in attaining an actionable schedule, but also develops a highly collaborative environment that facilitates buy-in and support for your project. In addition it will be difficult to incorporate rationalization into your project unless you are working directly with the business or application owners.

Q: What tools do you recommend for a server consolidation or virtualization project?

A: It's imperative to have a robust and comprehensive tool for capacity planning, including historical data. This tool can be utilized in every phase of your project. Other tools to support the project include modeling tools used in test consolidation scenarios. Finally, you'll need to evaluate and document tools and processes for each technology you wish to consolidate. The migration tools will need to support all the platforms you wish to use in your migration scenarios.
Q: What is the VMlibrary?

A: The VMlibrary (/vmlib) is simply a directory on your ESX Server that lets you organize the tools and files you need to manage and maintain your virtual infrastructure,

Q: Can ISOs be shared between ESX Servers?

A: If you place your VMlibrary on a LUN that's shared amongst your ESX Servers, you can share your ISO images or anything else you place in your VMlibrary.

Q: Why is Vmotion so cool?

A: Try it…and then imagine the possibilities and applications. You'll be a convert soon enough.

Q: You mentioned that additional ISVs were creating management capabilities for virtual infrastructures in their products. Which ones?

A: Look at HP Insight Manager, Dell OpenManage, IBM Director, BMC's Patrol product line, Computer Associates' Unicenter, and many others.
Q: I can't add a new virtual hard drive to my virtual machine. What should I do?

A: You may not have the appropriate permissions to add virtual hardware to the VM, or the VM may be powered on and won't allow the addition of virtual hardware while powered on.

Q: I just created a new virtual machine and attached to an existing disk. Every time I power on the VM, I get a blue screen. What could the problem be?

A: Make sure the OS type that you selected when you created the VM matches the OS type installed on the virtual disk. For example, if you selected Windows 2003 Standard for the VM when you created it, but the existing virtual disk has Windows 2000 Standard installed, you'll probably encounter issues.

Q: I followed the directions for Active Directory authentication, and I still can't log in using an account and password in AD. What should I do?

A: Check the time on your ESX Server and Active Directory and make sure they're synced up. Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within specific limits. You can also review the System event logs for clues.
Q: What is the most important aspect of deploying ESX Server and virtual machines?

A: The ability to provide service at least as good as that which you had with physical servers. With adherence to best practices, you should easily be able to provide this and exceed it by a phenomenal degree.

Q: ISOs have been mentioned in several of the chapters. Why are they so important?

A: Good administrators strive to never leave their chairs, cubes, or offices. If they do, they may just run into a user (we're kidding, of course). Having a library of ISOs can help you in this endeavor. In addition, they run a lot faster than regular CDs.

Q: What will happen if I deploy systems management software on the ESX Server itself?

A: If you're going to do this, make sure you allocate enough memory so that the application doesn't impact the performance of your ESX Server and thus your virtual machines. Also, use a system management package that is supported and test your installation on your ESX Server thoroughly. If you notice a degradation of performance, contact the systems management software vendor. The major vendors have instructions and best practices for deploying their products onto ESX Server.

Q: What is the most important best practice to follow?

A: The one that ensures your smooth evolution into a virtual infrastructure education. Learn every aspect of a virtual environment to the best of your ability. Be passionate about it and you'll reap the rewards. See the recommended reading list, troll the VMware Web site regularly, as well as other Web sites dedicated to virtualization such as p2v.net, vmguru.com, and virtual-strategy.com.
Q: Which version of VMware ESX Server supports Boot from SAN?

A: ESX Server 2.5 supports Boot from SAN but has the following limitations: ESX server had to be installed in boot from SAN mode, the HBA can only be used by the Service Console, LUN masking should be used to restrict other ESX servers from the boot LUN, the HBA of the boot LUN must be a QLogic HBA, and the boot LUN must be the lowest numbered LUN controlled by the storage processor.

Q: Where are log files for VMware ESX Server written to?

A: /var/logs/vmware

Q: What do you do if you forget the root password of the Service Console?

A: You will need to boot into single-user mode from the Service Console by selecting linux from the LILO boot menu and appending -s to your boot choice. This will boot the console into single-user mode and will allow you to use the passwd command to change the root user password.

Q: Why do I still see processes for my virtual machine when running the ps command on the Service Console even though my virtual machine is powered down?

A: If there is still a virtual console session running for your VM, you will still see processes associated with it for mouse, keyboard, and screen (MKS) even though it is powered off.

Q: I accidently unmounted the VMFS volume on my ESX Server. How can I re-mount the volume without re-booting

A: You can type mount t vmfs vmfs /vmfs
Q: What software is qualified for use with VMware 2.5.1?

A: Please see http://vmware.com/pdf/esx_backup_guide.pdf for an up-to-date list of software that's compatible with ESX.

Q: What SANs are compatible with ESX Server?

A: Please see http://vmware.com/pdf/esx_SAN_guide.pdf for details on ESX-to-SAN server compatibility.

Q: What are the certified backup tools for ESX?

A: Please see http://vmware.com/support/esx25/doc/backup_tools_links.html.

Q: Can I back up my entire virtual machine from the Service Console?

A: Yes, but it is not advised. The console services should be left alone to manage the entire virtual machine infrastructure. It's best that backups be performed by separating the applications and data from the operating systems because backups can become quite large very quickly. You should consider a backup of the environments that change frequently (data and applications) with an agent specifically designed to perform this function. A backup of those virtual disks that change infrequently and need VMFS formats should be backed up from the Service Console. These console-based backups should be performed in a powered-down or suspended approach (preferred), or a suspended environment using redo logs as an alternative. All backups performed from a systems console mode must be restored in an all-or-nothing approach. Recovery for a single file or directory can only be accomplished via a backup agent or from a backup to a SAN environment using a variety of different recovery/restoral techniques.
Q: I'm not able to connect to the Service Console over the network. What could the issue be?

A: You may have allocated the Service Console NIC to the VMkernel. Use vmkpcidivyi to reassign the NIC to the Service Console.

Q: I have a virtual machine that did not start up correctly, but now I can't power it down from the MUI or Virtual Center. How can I get this VM to shut down?

A: You can use the vmware-cmd utility to force a hard power down. The following syntax should work:

vmware-cmd /path-to-vm/vm-directory/vm.vmx stop hard

Q: I find using commands to be very difficult. Why can't I use X Windows on the Service Console?

A: You actually could run the X Windows system on the Service Console, but it will eat up valuable resources that are needed by the system to manage all the processes related to Virtualization. VMware specifically says not to run X Windows on the Service Console. So, it's best to just buck up and deal with it.

Q: Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to reboot?

A: Yes. You can run mountt vmfs vmfs /vmfs.

Q: How do I check the speed and duplex setting of the Service Console NIC? Also, how do I change it if needed?

A: You'll need to cat out the eth0.info file for your type of adapter. This file can be found at /proc/net/type-of-nic/eth0.info. To give you an example, our server has an Intel Pro 100 Nic for the Service Console, so for us to find the speed and duplex information we would type: cat /proc/net/PRO_LAN_Adapters/eth0.info.
Q: How long has Xen been around?

A: Since 2004, and they're located in Palo Alto, California. Hmm…what other virtualization company is in Palo Alto?

Q: What is a hypervisor?

A: In VMware parlance, it's the virtualization layer.

Q: Why did VMware limit its beta of ESX Server 3.0 to so few?

A: Good question…We don't know, and we hope that VMware's future beta programs are opened up to a larger audience.

Q: If I can't get a SAN, will local storage with a RAID device be sufficient?

A: Absolutely. You won't get some of the cooler tools like VMotion, but being virtual on local storage is better than remaining physical.