Virtualization is the need of the hour as the business is expanding and so is the need of multiple servers and space requirements. Virtualization is the answer to easy application deployment, maximum server utilization, and robust disaster recovery plans. To cater to this rising deployment of virtualization around the globe, VMware administrators are in great demand. Here we list out some the famous VMware interview questions and answers that applicable in 2016 and 2017.
In order to get a job in the capacity of VMware administrator, you have to answer the questions related to VMware virtualization technologies. Here are some of the vital questions asked during interviews and would definitely going to help you answer them confidently.
VMware Interview Questions & Answers in 2016/2017
What is a VMkernel?
VMkernel is an interface between VMs and the VMware ESX host. Its main function is to allocate memory, to schedule the CPUs and is necessary to run many of the services like vMotion, Fault tolerance, NFS, traffic management and iSCSI. VMkernel port can be configured on ESX server using a standard vSwitch .
What is the mode of communication between VMs on one server with other servers?
In networking, VMs can communicate with other VMs on a different server with the help of VMware port groups. The port group is associated with an uplink which a physical LAN port on a physical switch. The port group then acts as an interface for communication between vSwitch and physical switch to connect to another server in a network. The port group can be created by logging into the vSphere client.
What are VLAN and VLAN tagging and what types of tagging are available in vSphere?
VLAN. Despite the physical distribution of servers and other devices in a single or multiple LANs, the devices are able to communicate with each other as they are in a single LAN is called virtual LAN. Some of the benefits of VLAN include flexibility to relocate servers and workstations, sharing single broadcast and easy management of the network.
VLAN Tagging. The Ethernet frames have to travel through trunk links and to identify these frames navigating through trunk lines, VLAN tags are added to these frames. When it reaches the concluding end of the trunk line, the tag is removed and the Ethernet frame reaches the pre-defined access link so that the VLAN information remains unknown to the target link.
Types of ESX tagging. VMware vSphere is used for VLAN tagging in ESX. The three types of VLAN tagging possible in ESX are
· Virtual Guest Tagging
· External Switch tagging
What is the impact on HA,DRS, and FT if vCentre is down?
HA. High availability is managed by HA agent which is installed on vCenter server while configuring hosts. So even if vCenter Server is not working, HA will keep on working since HA is controlled by FDM agents.
DRS. In case vCenter is down, DRS will stop working since the distribution of VMs is a function of vCenter Server.
FT. Although you will not be able to create VMs, the already configured VMs will not be affected in case of vCenter outage.
What is 64-bit architecture and which version of ESX supports it?
The latest hardware and operating systems run on powerful and faster 64-bit architecture as compared to conventional 32-bit architecture. The ESX Server below 4.0 version were all built on 32-bit architecture. But the new ESX server 4.0 work on 64-bit platform and scalability is increased since it can support the VMs with up to 255Gb of RAM.
Explain the difference between type1 and Type 2 hypervisors.
The type 1 hypervisor is installed directly on the server host and does not require any pre-installed OS. It is also called Bare Metal hypervisor. The hypervisor1 is small software which is easy to install and does not consume any system resources. The main objective of type1 hypervisor is to manage different resources between operating systems installed on it. All the VMs and OS are independent of each other and problem in any one VM does not affect the other VMs.
Type 2, on the other hand, can be installed only on the operating system installed on the host server and dependent on host OS for all its functionality. If OS gets corrupted, the hypervisor and all the VMs get affected.
How is the clone different from the template in VMware?
· Template is the master copy of a Virtual machine and is used to create copies of other Virtual machines whereas a clone is just the copy of Virtual machine.
· A template can get converted back to VM to update the master VM copy with latest patches or updates but a clone, once created cannot be converted back to VM.
· A clone can be created while VM is in ON condition whereas the creation of template from a VM is not possible in ON condition.
· Cloning is of 2 types’ viz. Full clone and Linked clone. A full clone is entirely isolated clone and does not depend on its parent VM in all its operations whereas Linked clone shares virtual disk space with its parent VM. The template, on the other hand, is entirely an independent entity.
How can you use 3rd party backup tools in VMware?
There is an inbuilt backup framework called VCB (VMware consolidate backup) that allows you to use third party backup software to backup ESX virtual servers. VCB allows you to take both full and incremental backups.
Apart from having centralized backups of all virtual servers you can take file level as well as image-backups of ESX servers. During file level backup, VCB creates a snapshot of ESX server, mounts it and the mounted drive is then backup-ed through 3rd party software.
During the image level backup, the snapshot is done which is copied on the backup server, un-snapping of copy is done and finally, you can back the image with any 3rd party software.