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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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20.vmx (VM Config) file. What are the core services of VC ?VM provisioning . If it doesn't matches with the MACaddress in the OS this setting does not allow outgoing traffic from the VM. select edit settings. What to do to customize the linux/unix virtual machine clone.Virtual Machine Swap File.log . 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.vmss . 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. as these operating systems are available as opensource. and the service which corresponds toit is called as mgmt-vmware.Virtual Machine Suspended State file.The daemon associated with it is called vmwarehostd .Virtual Machine Snapshot file. 29. and it cannot be powered on once its changed totemplate. and the outgoing traffic will be allowed fromthe VM.Virtual Machine BIOS. 2 .log Old Log file 25. 18. so that the wizard will take theadvantage of it. So by setting RejectOption both MAC addresses will be remains same.vmx . and the incoming traffic will be allowed tothe VM.vmware.Virtual MAchine Snapshot Database.vswp . So by setting RejectOption both MAC addresses will be remains same. but the mandatory requirement is the VMshould be powered off.vmware-#. Task Scheduling and Event Logging 21. This is used to quick provisioning of VM's.0 we can add Memory and Processor along with HDD and NIC's while themachine running 26. What to do to customize the windows virtual machine clone. choose options tab and select boot option. 28.Virtual Machine Disk file. 22.vmdk .nvram . all the communication is visible to all the virtualmachines. set the delayhow much you want. check the /Opt size whether itis sufficient or not. What are the devices that can be added while the virtual Machine runningIn VI 3. 27.vmsd . so at the time of installtion ifyou are getting an error like " VC Agent service failed to install ". in other words all the packets are sent to all the ports on vSwitchIf the promiscuous mode set to Reject. What is Promiscuous Mode on vSwitch ? What happens if it sets to Accept?If the promiscuous mode set to Accept.?copy the sysprep files to Virtual center directory on the server. so that theintended virtual machine was able to see the communication.Virtual Machine Configuration File. What is a template ?We can convert a VM into Template.Current Log File. What are the files that make a Virtual Machine ?. 19.vmsn . 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. If it doesn't matches with the MACaddress in the OS this setting does not allow incoming traffic to the VM. the packets are sent to inteded port. you can see it in the . 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.?VC itself includes the customization tools. you can see it in the . Can we do vMotion between two datacenters ? If possible how it will be?Yes we can do vMotion between two datacenters. How to set the time delay for BIOS screen for a Virtual Machine?Right Click on VM.5 we can add Hard Disk and NIC's while the machine running.In vSphere 4.vmx (VM Config) file. 23.17. 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.

if the template in one datacenter.. Does cloning from template happens between two datacenters ?Yes.30. it can. you need to remove it to take asnapshot. If it is mapped as virtualthen we can take a snapshot of it. 31.If you configure the VM with Mapped LUN's as physical. then the snapshot failed. we can deploy the vm from that template inanother datacenter without any problem. 32. 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. 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 .

Used for Service Console Communications3. Virtual Nic(s) on Virtual Machine(s) ----->Physical Nic on the ESX Server (Virtual Switch .Used for Virtual Machine Network 2. So every vSwitch supports upto 1016 ports.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.333. To restart ssh service on vmwareservice sshd restart 6. Path for the struts-config.222. 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. and 4 . So that vMotion succeedsAll the Virtual Machines are connected to one vSwitch with Different VLANS. 2. it's akernel developed by VMWare Company. That is thereason vmware included the VLAN tagging for vSwitches. 16. Service Console Port Group .config ksdevice=eth0location device name 9. Virtual Network in Simple……………….444:/data/KS. So this port group enables communication between vSwitch and Physical Switch to connect vm'sto Physical Machine's 15. iSCSI. Does the vSwitches support VLAN Tagging? Why?Yes. What are the type of communications which requires an IP address for sure ?Service Console and VMKernel (VMotion and iSCSI). we need to install a separate physical nic (vSwitch) for every VLAN. In the ESX Server licensing features VMotion License is showing as Not used.Used for VMotion. NFS Communications 11. otherwise if the virtual machines in an esx host are connectedto different VLANS.1. these communications does not happen without anip address (Whether it is a single or dedicated) 13.xml/usr/lib/vmware/webAccess/tomcat/apache-tomcat5. why?Even though the license box is selected. 3.17/webapps/ui/WEB-INF/ 8. the portmust be trunked with the correct VLAN ID. The service console is developed based up on Redhat Linux Operating system. To start the scripted install the command isesx ks=nfs:111. What is a VLAN ?A VLAN is a logical configuration on the switch port to segment the IP Traffic. it is used to manage theVMKernel 4. For this to happen. Virtual Machine Port Group . VMKernel Port Group . 12. The vSwitches support VLAN Tagging. you enable the VMotionoption for specific vSwitch 14.5. 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. so that it takes the help of the 3rd party operating system. it shows as "License Not Used" until. To restart host agent(vmware-hostd) on vmware esx server service mgmt-vmware restart 7. The VMKernel can't boot it by itself. VMWare Kernel is a Proprietary Kenral and is not based on any of the UNIX operating systems. To restart webaccess service on vmwareservice vmware-webaccess restart – this will restart apache tomcat app 5. InVMWare case the kernel is booted by RedHat Linux operating system which is known as service console. What is the use of a Port Group?The port group segregates the type of communication.

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

so that the wizard will take the advantage of it.. open local sec policy. select edit settings. What to do to customize the linux/unix virtual machine clone. Does cloning from template happens between two datacenters ?Yes. The user should have "Logon as service" privileges . To open the guided consolidation tool. If it is mapped as virtual then we can take a snapshot of it.24. How to set the time delay for BIOS screen for a Virtual Machine?Right Click on VM. This isused to quick provisioning of VM's. Its not a backup service. 33.26. what are the user requirements ?The user must be member of administrator. as these operating systems are available as open source. we can deploy the vm from that template in another datacenter without any problem. 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.?copy the sysprep files to Virtual center directory on the server.To give auser these privileges. select Logon as service policy and add the user the user shouldhave read access to AD to send queries 6 . set the delay how muchyou want. 29. you need to remove it to take a snapshot. it can. 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. choose options tab and select boot option. then the snapshot failed. What is a template ?We can convert a VM into Template. that supports 3rd party utilities to take backups of ESX servers and VirtualMachines.26. What to do to customize the windows virtual machine clone.If you configure the VM with Mapped LUN's as physical. 28. 30. if the template in one datacenter.?VC itself includes the customization tools. and it cannot be powered on once its changed to template. What is VMWare consolidated backup ?It is a backup framework. 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. 27.