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30 Important Virtualization-VMware Interview Questions with Answers Written by ShaukatWednesday, 24 August 2011 11:06 1.

VMWare Kernel is a Proprietary Kenral and is not based on any of the UNIX operatingsystems, it's a kernel developed by VMWare Company. 2. The VMKernel can't boot it by itself, so that it takes the help of the 3rd party operatingsystem. In VMWare case the kernel is booted by RedHat Linux operating system which isknown as service console. 3. The service console is developed based up on Redhat Linux Operating system, it is used tomanage the VMKernel 4. To restart webaccess service on vmwareservice vmware-webaccess restart – this will restart apache tomcat app 5. To restart ssh service on vmwareservice sshd restart 6. To restart host agent(vmware-hostd) on vmware esx serverservice mgmt-vmware restart 7. Path for the struts-config.xml /usr/lib/vmware/webAccess/tomcat/apache-tomcat-5.5.17/webapps/ui/WEBINF/ 8. To start the scripted install the command isesx ks=nfs:111.222.333.444:/data/KS.config ksdevice=eth0location device name 9. Virtual Network in Simple……………….Virtual Nic(s) on Virtual Machine(s) ----->Physical Nic on the ESX Server (Virtual Switch - 56 Ports) ----->Physical Switch Port Should be trunked with all the VLANS to which the VM's needaccessAll the ESX servers should be configured with Same number of Physical Nics (vSwitches) andConnectivity also should be same, So that vMotion succeedsAll the Virtual Machines are connected to one vSwitch with Different VLANS, this means thePhysical Nic(vSwitch) needs to be trunked with the same VLANS on the Physical Switch Port 10 What are the three port groups present in ESX server networking1. Virtual Machine Port Group - Used for Virtual Machine Network2. Service Console Port Group - Used for Service Console Communications3. VMKernel Port Group - Used for VMotion, iSCSI, NFS Communications 11. What is the use of a Port Group?The port group segregates the type of communication. 12. What are the type of communications which requires an IP address for sure ?Service Console and VMKernel (VMotion and iSCSI), these communications does not happen 13. In the ESX Server licensing features VMotion License is showing as Not used, why?Even though the license box is selected, it shows as "License Not Used" until, you enable theVMotion option for specific vSwitch 14. How the Virtual Machine Port group communicationworks ?All the vm's which are configured in VM Port Group are able to connect to the physicalmachines on the network. So this port group enables communication between vSwitch andPhysical Switch to connect vm's to Physical Machine's 15. What is a VLAN ?A VLAN is a logical configuration on the switch port to segment the IP Traffic. For this tohappen, the port must be trunked with the correct VLAN ID. 16. Does the vSwitches support VLAN Tagging? Why?Yes, The vSwitches support VLAN Tagging, otherwise if the virtual machines in an esx hostare connected to different VLANS, we need to install a separate physical nic (vSwitch) for everyVLAN. That is the reason vmware included the VLAN tagging for vSwitches. So every vSwitchsupports upto 1016 ports, and BTW they can support 1016 VLANS if needed, but an ESXserver doesn’t support that many VM’s. :)

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What is a template ?We can convert a VM into Template. What is Forged Transmits ? What happens if it is set to Accept ?When we create a virtual machine the configuration wizard generates a MAC address for thatmachine. as these operating systems are available as opensource. in the event of VC agent failure just restart the service by typingthe following command at the service console " service mgmt-vmware restart "VC agent installed on the ESX server when we add it to the VC. What are the files that make a Virtual Machine ?. select edit settings.vmss . What to do to customize the windows virtual machine clone.5 we can add Hard Disk and NIC's while the machine running. So by setting RejectOption both MAC addresses will be remains same. So by setting RejectOption both MAC addresses will be remains same.Virtual Machine Disk file.Virtual Machine Snapshot file. 18. 22.?VC itself includes the customization tools. If it doesn't matches with the MACaddress in the OS this setting does not allow incoming traffic to the VM. set the delayhow much you want. but the mandatory requirement is the VMshould be powered off. 2 .vswp .nvram .vmdk .Virtual Machine Configuration File.17. and the incoming traffic will be allowed tothe VM. What is VC agent? and what service it is corresponded to? What are the minimum req's forVC agent installation ?VC agent is an agent installed on ESX server which enables communication between VC andESX server. 23. This is used to quick provisioning of VM's. What is Promiscuous Mode on vSwitch ? What happens if it sets to Accept?If the promiscuous mode set to Accept.log .?copy the sysprep files to Virtual center directory on the server.Virtual MAchine Snapshot Database. and the outgoing traffic will be allowed fromthe VM.Virtual Machine BIOS.vmx . 28. How can you edit VI Client Settings and VC Server Settings ?Click Edit Menu on VC and Select Client Settings to change VI settingsClick Administration Menu on VC and Select VC Management Server Configuration to ChangeVC Settings 24. What are the core services of VC ?VM provisioning . How to set the time delay for BIOS screen for a Virtual Machine?Right Click on VM.vmware.0 we can add Memory and Processor along with HDD and NIC's while themachine running 26. and the service which corresponds toit is called as mgmt-vmware.Virtual Machine Suspended State file. so at the time of installtion ifyou are getting an error like " VC Agent service failed to install ".Virtual Machine Swap File. so that the wizard will take theadvantage of it. check the /Opt size whether itis sufficient or not. so that theintended virtual machine was able to see the communication.vmx (VM Config) file. and it cannot be powered on once its changed totemplate. you can see it in the .The daemon associated with it is called vmwarehostd . all the communication is visible to all the virtualmachines. 29.Current Log File. What to do to customize the linux/unix virtual machine clone.vmsn .log Old Log file 25. Can we do vMotion between two datacenters ? If possible how it will be?Yes we can do vMotion between two datacenters. What are the devices that can be added while the virtual Machine runningIn VI 3. in other words all the packets are sent to all the ports on vSwitchIf the promiscuous mode set to Reject.vmx (VM Config) file. the packets are sent to inteded port. What is MAC address Changes ? What happens if it is set to Accept ?When we create a virtual machine the configuration wizard generates a MAC address for thatmachine.vmsd .vmware-#. 20. choose options tab and select boot option.In vSphere 4. 19. Task Scheduling and Event Logging 21. 27. you can see it in the . If it doesn't matches with the MACaddress in the OS this setting does not allow outgoing traffic from the VM.

30. Does cloning from template happens between two datacenters ?Yes.If you configure the VM with Mapped LUN's as physical. What are the settings that are taken into to consideration when we initiate a snapshot ?Virtual Machine Configuration (What hardware is attached to it)State of the Virtual Machine Hard Disk file ( To revert back if needed) 3 . What are the common issues with snapshots? What stops from taking a snapshot and howto fix it ?If you configure the VM with Mapped LUN's. 31. you need to remove it to take asnapshot. it can. If it is mapped as virtualthen we can take a snapshot of it.. we can deploy the vm from that template inanother datacenter without any problem. if the template in one datacenter. then the snapshot failed. 32.

444:/data/KS. What is the use of a Port Group?The port group segregates the type of communication. 3. 16.5. we need to install a separate physical nic (vSwitch) for every VLAN. What are the type of communications which requires an IP address for sure ?Service Console and VMKernel (VMotion and iSCSI). How the Virtual Machine Port group communication works ?All the vm's which are configured in VM Port Group are able to connect to the physical machines on thenetwork. it's akernel developed by VMWare Company. To start the scripted install the command isesx ks=nfs:111. otherwise if the virtual machines in an esx host are connectedto different VLANS. it shows as "License Not Used" until. so that it takes the help of the 3rd party operating system.Used for Virtual Machine Network 2.56 Ports) ----->Physical Switch Port Should be trunked with all the VLANS to which the VM's need accessAll the ESX servers should be configured with Same number of Physical Nics (vSwitches) andConnectivity also should be same. Virtual Nic(s) on Virtual Machine(s) ----->Physical Nic on the ESX Server (Virtual Switch . That is thereason vmware included the VLAN tagging for vSwitches. The vSwitches support VLAN Tagging. the portmust be trunked with the correct VLAN ID.Used for Service Console Communications3. To restart host agent(vmware-hostd) on vmware esx server service mgmt-vmware restart 7. and 4 . Virtual Machine Port Group . VMKernel Port Group . Service Console Port Group . What is a VLAN ?A VLAN is a logical configuration on the switch port to segment the IP Traffic. VMWare Kernel is a Proprietary Kenral and is not based on any of the UNIX operating systems. To restart ssh service on vmwareservice sshd restart 6. So every vSwitch supports upto 1016 ports. InVMWare case the kernel is booted by RedHat Linux operating system which is known as service console.config ksdevice=eth0location device name 9. you enable the VMotionoption for specific vSwitch 14.1. For this to happen. why?Even though the license box is selected. The service console is developed based up on Redhat Linux Operating system. NFS Communications 11. Virtual Network in Simple………………. iSCSI.Used for VMotion. 12.333. In the ESX Server licensing features VMotion License is showing as Not used. Does the vSwitches support VLAN Tagging? Why?Yes.222. To restart webaccess service on vmwareservice vmware-webaccess restart – this will restart apache tomcat app 5. Path for the struts-config. 2. The VMKernel can't boot it by itself. So that vMotion succeedsAll the Virtual Machines are connected to one vSwitch with Different VLANS. these communications does not happen without anip address (Whether it is a single or dedicated) 13.xml/usr/lib/vmware/webAccess/tomcat/apache-tomcat5. this means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on the Physical Switch Port 10 What are the three port groups present in ESX server networking1. So this port group enables communication between vSwitch and Physical Switch to connect vm'sto Physical Machine's 15. it is used to manage theVMKernel 4.17/webapps/ui/WEB-INF/ 8.

but an ESX server doesn’t support that many VM’s. 23.vmss . Task Scheduling and Event Logging 21.Virtual MAchine Snapshot Database. Can we do vMotion between two datacenters ? If possible how it will be?Yes we can do vMotion between two datacenters.vswp . How can you edit VI Client Settings and VC Server Settings ?Click Edit Menu on VC and Select Client Settings to change VI settingsClick Administration Menu on VC and Select VC Management Server Configuration to Change VCSettings 24.Virtual Machine Swap File. so at the time of installtion if you aregetting an error like " VC Agent service failed to install ".nvram .vmx . and the incoming traffic will be allowed to the VM. in other words all the packets are sent to all the ports on vSwitchIf the promiscuous mode set to Reject.Virtual Machine BIOS.vmsn .vmx (VM Config) file.Virtual Machine Configuration File. 20.log Old Log file 25. What is Promiscuous Mode on vSwitch ? What happens if it sets to Accept?If the promiscuous mode set to Accept. so that the intended virtualmachine was able to see the communication.vmsd .Current Log File. the packets are sent to inteded port. If it doesn't matches with the MAC address in the OS this settingdoes not allow incoming traffic to the VM. If it doesn't matches with the MAC address in the OS this settingdoes not allow outgoing traffic from the VM. and the service which corresponds to it is called asmgmt-vmware.In vSphere 4.vmx (VM Config) file.5 we can add Hard Disk and NIC's while the machine running.BTW they can support 1016 VLANS if needed.Virtual Machine Suspended State file.0 we can add Memory and Processor along with HDD and NIC's while the machine running 5 .The daemon associated with it is called vmwarehostd .log . in the event of VC agent failure just restart the service by typing the following command atthe service console" service mgmt-vmware restart "VC agent installed on the ESX server when we add it to the VC. What are the files that make a Virtual Machine ?.vmware-#. What are the devices that can be added while the virtual Machine runningIn VI 3. 18.vmware. So by setting Reject Option both MAC addresses will beremains same. all the communication is visible to all the virtual machines. What is Forged Transmits ? What happens if it is set to Accept ?When we create a virtual machine the configuration wizard generates a MAC address for that machine. What is VC agent? and what service it is corresponded to? What are the minimum req's for VC agentinstallation ?VC agent is an agent installed on ESX server which enables communication between VC and ESX server.Virtual Machine Snapshot file.vmdk . What are the core services of VC ?VM provisioning . and the outgoing traffic will be allowed from the VM. 22. you can see it in the . So by setting Reject Option both MAC addresses will beremains same. 19.Virtual Machine Disk file. but the mandatory requirement is the VM should be powered off. youcan see it in the . :)17. What is MAC address Changes ? What happens if it is set to Accept ?When we create a virtual machine the configuration wizard generates a MAC address for that machine. check the /Opt size whether it is sufficient or not.

What to do to customize the windows virtual machine clone.26.26. 30. What are the settings that are taken into to consideration when we initiate a snapshot ?Virtual Machine Configuration (What hardware is attached to it)State of the Virtual Machine Hard Disk file ( To revert back if needed)State of the Virtual Machine Memory (if it is powered on) 31.?copy the sysprep files to Virtual center directory on the server. This isused to quick provisioning of VM's. select Logon as service policy and add the user the user shouldhave read access to AD to send queries 6 . What is a template ?We can convert a VM into Template. choose options tab and select boot option. 27..If you configure the VM with Mapped LUN's as physical. so that the wizard will take the advantage of it. then the snapshot failed. we can deploy the vm from that template in another datacenter without any problem. if the template in one datacenter.?VC itself includes the customization tools. it can. 28. If it is mapped as virtual then we can take a snapshot of it. What are the requirements for Converting a Physical machine to VM ?An agent needs to be installed on the Physical machineVI client needs to be installed with Converter Plug-inA server to import/export virtual machines 32. select edit settings. as these operating systems are available as open source.24. The user should have "Logon as service" privileges . 33. How to set the time delay for BIOS screen for a Virtual Machine?Right Click on VM. what are the user requirements ?The user must be member of administrator. What to do to customize the linux/unix virtual machine clone. What are the common issues with snapshots? What stops from taking a snapshot and how to fix it ?If you configure the VM with Mapped LUN's. and it cannot be powered on once its changed to template. Its not a backup service. Does cloning from template happens between two datacenters ?Yes. set the delay how muchyou want. To open the guided consolidation tool.To give auser these privileges. What is VMWare consolidated backup ?It is a backup framework. that supports 3rd party utilities to take backups of ESX servers and VirtualMachines. you need to remove it to take a snapshot. open local sec policy. 29.