Interview Questions.

Question 1. What Is A Hypervisor?

Answer :

It is a application that lets in multiple working structures to percentage a single hardware host. Each operating gadget seems to have the host's processor, reminiscence, and different assets all to itself. However, the hypervisor is surely controlling the host processor and resources, allocating what is wanted to every working gadget in flip and ensuring that the visitor operating systems (known as digital machines) can not disrupt every other.

Question 2. What Is The Use Of Vmware Tools?

Answer :

VMware Tools is a set of utilities that complements the performance of the virtual machine's visitor operating gadget and improves management of the digital system. Without VMware Tools established in your visitor working machine, guest overall performance lacks essential functionality.
Installing VMware Tools eliminates or improves those problems:

Low video resolution
Inadequate color intensity
Incorrect display of network speed
Restricted movement of the mouse
Inability to duplicate and paste and drag-and-drop files
Missing sound
Provides the capability to take quiesced snapshots of the guest OS
Synchronizes the time within the guest operating system with the time on the host
Provides aid for visitor-bound calls created with the VMware VIX API
Hyper-V Interview Questions
Question three. If The Vcenter Server Goes Down With A Situation That It Was Pre Configured With Vsphere Ha And Drs, So After Power Down Will Ha And Drs Perform Their Task?

Answer :

vSphere HA is not dependent on vCenterserver for its operations as whilst HA is configured it installs an agent into each host which does its component and is not depending on vCenterserver. Also HA doesnot makes use of vMotion, it justs restarts the vms into another host anyways of host failure.
Further vSphere DRS is very a lot depending on vCenterserver because it makes use of vMotion for its movement for live migration of vms among multiple hosts so in case vCenterserver is going down the vMotion won't work main to failure of DRS.

Question 4. How Is A Master Host Elected In Vsphere Ha Environment?

Answer :

When vSphere HA is enabled for a cluster, all energetic hosts (the ones no longer in standby or protection mode, or not disconnected) take part in an election to select the cluster's master host. The host that mounts the finest wide variety of datastores has a bonus inside the election. Only one master host typically exists according to cluster and all different hosts are slave hosts.

If the grasp host fails, is shut down or installed standby mode, or is eliminated from the cluster a brand new election is held.

Question five. How Does Vsphere Ha Works?

Answer :

When we configure multiple hosts for HA cluster, a unmarried host is routinely elected because the grasp host. The master host communicates with vCenter Server and video display units the state of all protected virtual machines and of the slave hosts. When you add a number to a vSphere HA cluster, an agent is uploaded to the host and configured to communicate with different sellers in the cluster.

Red Hat Linux System Administration Interview Questions
Question 6. What Are The Monitoring Methods Used For Vsphere Ha?

Answer :

The Master and Slave hosts makes use of  kinds of monitoring the fame of the hosts

Datastore Heartbeat
Network Heartbeat
Question 7. What Are The Roles Of Master Host In Vsphere Ha?

Answer :

Monitoring the kingdom of slave hosts. If a slave host fails or turns into unreachable, the grasp host identifies which virtual machines want to be restarted.
Monitoring the electricity nation of all covered virtual machines. If one virtual machine fails, the master host ensures that it's miles restarted. Using a neighborhood placement engine, the master host also determines where the restart must be completed.
Managing the lists of cluster hosts and guarded digital machines.
Acting as vCenter Server control interface to the cluster and reporting the cluster fitness nation.
VMware Infrastructure with ESX Server and VirtualCenter Interview Questions
Question 8. What Is The Difference Between Type 1 And Type 2 Hypervisor?

Answer :

Type 1 Hypervisor:

This is likewise called Bare Metal or Embedded or Native Hypervisor.
It works directly at the hardware of the host and might screen running systems that run above the hypervisor.
It is completely impartial from the Operating System.
The hypervisor is small as its fundamental mission is sharing and managing hardware sources among exceptional working systems.
A principal gain is that any issues in a single digital machine or guest operating machine do now not have an effect on the opposite guest running structures strolling on the hypervisor.
Examples: VMware ESXi Server, Microsoft Hyper-V, Citrix/Xen Server
Type 2 Hypervisor :

This is also referred to as Hosted Hypervisor.
In this case, the hypervisor is mounted on an running gadget and then supports other operating systems above it.
It is completely dependent on host Operating System for its operations
While having a base running device permits better specification of guidelines, any troubles inside the base running gadget a ffects the whole machine as well even though the hypervisor jogging above the base OS is cozy.
Examples: VMware Workstation, Microsoft Virtual PC, Oracle Virtual Box
Question nine. What Happens If Vcenter Server Is Offline When A Failover Event Occurs?

Answer :

When Fault Tolerance is configured for a virtual device, vCenter Server want not be on line for FT to paintings. Even if vCenter Server is offline, failover nonetheless occurs from the Primary to the Secondary virtual gadget. Additionally, the spawning of a brand new Secondary digital system also happens without vCenter Server.

Citrix NetScaler Interview Questions
Question 10. How Many Virtual Cpus Can I Use On A Fault Tolerant Virtual Machine ?

Answer :

vCenter Server 4.X and vCenter Server 5.X support 1 digital CPU according to covered digital gadget.

Question eleven. In A Cluster With More Than 3 Hosts, Can You Tell Fault Tolerance Where To Put The Fault Tolerance Virtual Machine Or Does It Chose On Its Own?

Answer :

You can region the authentic (or Primary virtual gadget). You have complete manipulate with DRS or vMotion to assign it to any node. The placement of the Secondary, while created, is automated primarily based on the available hosts. But while the Secondary is created and positioned, you may vMotion it to the preferred host.

Microsoft Virtual Server Interview Questions
Question 12. What Is Vmware Fault Tolerance?

Answer :

VMware Fault Tolerance gives non-stop availability to programs running in a digital gadget, preventing downtime and records loss within the event of server disasters.
VMware Fault Tolerance, when enabled for a digital machine, creates a stay shadow instance of the number one, running on some other bodily server.
The two instances are stored in virtual lockstep with every other using VMware vLockstep generation
The two digital machines play the exact same set of occasions, because they get the exact same set of inputs at any given time.
The two virtual machines continuously heartbeat against every other and if either digital device example loses the heartbeat, the opposite takes over straight away. The heartbeats are very common, with millisecond intervals, making the failover on the spot with out a loss of facts or kingdom.
VMware Fault Tolerance requires a committed network connection, separate from the VMware VMotion community, between the two physical servers.
Hyper-V Interview Questions
Question 13. What Is Vmware Drs And How Does It Works?

Answer :

Here DRS stands for Distributed Resource Scheduler which dynamically balances resource across various host underneath Cluster or resource pool:

VMware DRS allows users to outline the policies and guidelines that decide how digital machines percentage assets and the way those assets are prioritized among a couple of digital machines.
Resources are allocated to the virtual gadget by using either migrating it to any other server with greater available assets or by making extra “area” for it on the same server by way of migrating other virtual machines to exceptional servers.
The live migration of digital machines to distinct physical servers is achieved completely transparent to end-users via VMware VMotion
VMware DRS can be configured to perform in either computerized or guide mode. In automatic mode, VMware DRS determines the pleasant viable distribution of digital machines among special bodily servers and mechanically migrates digital machines to the maximum suitable physical servers. In guide mode, VMware DRS provides a recommendation for most excellent placement of digital machines, and leaves it to the system administrator to determine whether or not to make the change.
Question 14. What Is Storage Vmotion?

Answer :

Storage vMotion is similar to vMotion in the experience that "some thing" related to the VM is moved and there is no downtime to the VM visitor and quit customers. However, with SVMotion the VM Guest stays on the server that it resides on but the digital disk for that VM is what moves.
With Storage vMotion, you can migrate a virtual system and its disk documents from one datastore to some other even as the virtual gadget is jogging.
You can select to location the digital device and all its disks in a single area, or choose separate locations for the virtual machine configuration report and every virtual disk.
During a migration with Storage vMotion, you may transform virtual disks from Thick-Provisioned Lazy Zeroed or Thick-Provisioned Eager Zeroed to Thin-Provisioned or the reverse.
Perform stay migration of virtual machine disk files throughout any Fibre Channel, iSCSI, FCoE and NFS garage
Question 15. What Is The Difference Between Vmware Ha And Vmotion?

Answer :

VMware HA is used inside the event when any of the hosts internal a cluster fails then all the virtual machines jogging underneath it are restarted on exceptional host inside the equal cluster.

Now HA is depending on vMotion to carry out stay migration of the vms to specific host so vMotion is simply used for the migration motive between multiple hosts which is likewise utilized by other capability like DRS.

NOTE: Anyhow HA can work very will with out vMotion as its primary functionality is to restart the vm from the affected host to the operating host but this may be carrier affecting because the vms may be 'powered off' and then 'powered on' on the new host.

VMware NSX Interview Questions
Question sixteen. What Is Vmware Ha?

Answer :

VMware HA i.E. High Availability which goes on the host degree and is configured at the Cluster.
A Cluster configured with HA will migrate and restart all the vms going for walks underneath any of the host in case of any host-degree failure automatically to any other host underneath the identical cluster.
VMware HA continuously monitors all ESX Server hosts in a cluster and detects failures.
VMware HA agent positioned on each host keeps a heartbeat with the other hosts inside the cluster using the provider console network. Each server sends heartbeats to the others servers within the cluster at five-2nd intervals. If any servers lose heartbeat over 3 consecutive heartbeat intervals, VMware HA initiates the failover movement of restarting all affected virtual machines on other hosts.
You can set virtual gadget restart priority in case of any host failure relying upon the critical nature of the vm.
NOTE: Using HA in case of any host failure with RESTART the vms on distinct host so the vms country might be interrupted and it is not a stay migration

Question 17. What Is A Snapshot?

Answer :

A snapshot is a “factor in time photograph” of a virtual guest running system (VM). That image contains an image of the VMs disk, RAM, and devices at the time the photograph changed into taken. With the photograph, you can go back the VM to that point in time, every time you pick. You can take snapshots of your VMs, regardless of what visitor OS you've got and the photo capability may be used for capabilities like performing picture level backups of the VMs without ever shutting them down.

Advanced Linux Interview Questions
Question 18. What Is Vdi?

Answer :

VDI stands for Virtual Desktop Infrastructure where quit user bodily system like laptop or pc are virtualized because of which VMware described VDI as "turning in computers from the statistics center”.
Once VDI is used the stop user hook up with their computer the usage of a device referred to as thin purchaser.
The give up consumer also can hook up with their laptop using VMware Horizon View installed on any computer or cell devices
Red Hat Linux System Administration Interview Questions
Question 19. What Is Promiscuous Mode In Vmware?

Answer :

Promiscuous mode is a safety coverage which can be described at the virtual transfer or portgroup level
A digital machine, Service Console or VMkernel community interface in a portgroup which allows use of promiscuous mode can see all network traffic traversing the virtual transfer.
If this mode is ready to reject, the packets are sent to supposed port in order that the supposed virtual device will best be capable of see the communication.
Example: In case you're the use of a virtual xp internal any Windows VM. If promiscuous mode is ready to reject then the digital xp may not be capable of join the network except promiscuous mode is enabled for the Windows VM.
Question 20. What Is The Difference Between Thick Provision Lazy Zeroed, Thick Provision Eager Zeroed And Thin Provision?

Answer :

Thick Provision Lazy Zeroed

Creates a virtual disk in a default thick layout.
Space required for the virtual disk is allotted while the digital disk is created.
Data ultimate on the physical tool isn't always erased during advent, however is zeroed out on demand at a later time on first write from the virtual system.
Using the default flat virtual disk layout does now not 0 out or do away with the possibility of recovering deleted documents or restoring vintage records that might be gift in this allotted area.
You can not convert a flat disk to a skinny disk.
Thick Provision Eager Zeroed

A type of thick virtual disk that helps clustering functions inclusive of Fault Tolerance.
Space required for the digital disk is allocated at creation time.
In contrast to the flat format, the statistics last on the bodily tool is zeroed out when the virtual disk is created.
It might take a lot longer to create disks in this format than to create other varieties of disks.
Thin Provision

It presents on on-demand allocation of blocks of statistics.
All the space allocated at the time of introduction of digital disk isn't always applied at the tough disk, alternatively handiest the dimensions with applied records is locked and the scale will increase as the amount of facts is expanded at the disk.
With thin provisioning, garage capability utilization performance can be robotically pushed up in the direction of one hundred% with very little administrative overhead.
VMware Interview Questions
Question 21. What Is The Difference Between The Vsphere Esx And Esxi Architectures?

Answer :

VMware ESX and ESXi are both bare metal hypervisor architectures that installation directly on the server hardware.

Although neither hypervisor architectures is predicated on an OS for resource control, the vSphere ESX structure trusted a Linux running gadget, called the Console OS (COS) or provider console, to carry out  management functions: executing scripts and putting in third-birthday party agents for hardware tracking, backup or systems control.

In the vSphere ESXi architecture, the provider console has been removed. The smaller code base of vSphere ESXi represents a smaller “attack surface” and much less code to patch, improving reliability and protection.

Question 22. What Is A .Vmdk File?

Answer :

This is not the record containing the uncooked statistics. Instead it's miles the disk descriptor document which describes the scale and geometry of the digital disk report. This file is in textual content layout and incorporates the call of the –flat.Vmdk report for which it is related to and also the tough power adapter type, power sectors, heads and cylinders, etc. One of those documents will exist for every virtual hard power that is assigned on your virtual gadget. You can tell which –flat.Vmdk document it's far associated with by commencing the record and looking at the Extent Description subject.

Question 23. What Are The Different Types Of Virtualization?

Answer :

Server Virtualization – consolidating multiple physical servers into virtual servers that run on a single physical server.
Application Virtualization – an software runs on any other host from wherein it is established in a selection of ways. It may be executed through utility streaming, computing device virtualization or VDI, or a VM bundle (like VMware ACE creates with a player). Microsoft Softgrid is an example of Application virtualization.
Presentation Virtualization – This is what Citrix Met body (and the ICA protocol) as well as Microsoft Terminal Services (and RDP) are able to create. With presentation virtualization, an software definitely runs on every other host and all that you see on the purchaser is the screen from where it is run.
Network Virtualization – with network virtualization, the network is “carved up” and may be used for multiple functions which include strolling a protocol analyzer inner an Ethernet transfer. Components of a virtual community should consist of NICs, switches, VLANs, community storage devices, virtual community bins, and network media.
Storage Virtualization – with storage virtualization, the disk/information storage on your information is consolidated to and controlled by a digital garage device. The servers related to the garage machine aren’t aware of wherein the data absolutely is. Storage virtualization is now and again defined as “abstracting the logical garage from the physical storage.
Vmware Vsphere Interview Questions
Question 24. What Is Vmware Vmotion And What Are Its Requirements?

Answer :

VMware VMotion allows the stay migration of strolling virtual machines from one bodily server to every other with zero downtime.

VMotion helps you to:

Automatically optimize and allocate entire swimming pools of sources for maximum hardware usage and  availability.
Perform hardware upkeep without any scheduled downtime.
Proactively migrate digital machines faraway from failing or under performing servers.
Below are the pre-requisites for configuring vMotion :

Each host must be effectively licensed for vMotion
Each host must meet shared storage requirements
vMotion migrates the vm from one host to every other which is best viable with each the host are sharing a common storage or to any garage handy via each the source and target hosts. 
A shared garage may be on a Fibre Channel garage place community (SAN), or may be implemented using iSCSI SAN and NAS.
If you operate vMotion to migrate digital machines with raw device mapping (RDM) files, make sure to maintain steady LUN IDs for RDMs across all participating hosts.
Each host have to meet the networking necessities
Configure a VMkernel port on every host.
Dedicate at least one GigE adapter for vMotion.
Use as a minimum one 10 GigE adapter if you migrate workloads that have many reminiscence operations.
Use jumbo frames for best vMotion overall performance.
Ensure that jumbo frames are enabled on all network devices that are on the vMotion course inclusive of physical NICs, bodily switches and virtual switches.
VMware Infrastructure with ESX Server and VirtualCenter Interview Questions
Question 25. What Is The Difference Between Clone And Template In Vmware?

Answer :

Clone

A clone is a copy of virtual device.
You can't convert lower back the cloned Virtual Machine.
A Clone of a Virtual Machine can be created while the Virtual Machine is powered on
Cloning can be carried out in two ways specifically Full Clone and Linked Clone.
A full clone is an independent reproduction of a digital device that stocks not anything with the discern digital system after the cloning operation. Ongoing operation of a full clone is entirely break free the figure digital gadget.
A related clone is a copy of a virtual gadget that stocks virtual disks with the discern virtual device in an ongoing way. This conserves disk space, and permits more than one virtual machines to apply the identical software installation.
Cloning a virtual machine can shop time in case you are deploying many comparable virtual machines. You can create, configure, and deploy software program on a single virtual gadget, and then clone it multiple instances, rather than growing and configuring each digital system for my part.
Template

A template is a grasp copy or a baseline picture of a virtual system that can be used to create many clones.
Templates can not be powered on or edited, and are more tough to alter than normal virtual device.
You can convert the template lower back to Virtual Machine to replace the base template with the brand new released patches and updates and to install or improve any software program and again convert again to template for use for future deployment of Virtual Machines with the modern patches.
Convert virtual Machine to template can not be accomplished, whilst Virtual device is powered on.  Only Clone to Template can be accomplished whilst the Virtual Machine is powered on.
A template gives a more comfortable manner of maintaining a virtual system configuration that you want to install in many instances.
When you clone a digital device or deploy a virtual machine from a template, the resulting cloned digital gadget is impartial of the original digital machine or template.