What is virtualization? Why you choose VMware?
Ans :
-
Virtualization is providing to run multiple operating systems
on a single hardware.
Virtualization is the single most effective way to reduce IT expenses
while boosting efficiency and agility
—
not just for large enterprises,
but for small and midsize businesses too.
VMware is the leader in Server virtualization and it has very good
features when we are comparing to other vendors who will provide
server virtualization.
Q :
-
What is a Hypervisor?
Ans :
-
It is a program that allows multiple operating systems to share a single
hardware host. Each operating system appears to have the host’s processor,
memory, and other resources all to itself. However, the hypervisor is actually
controlling the host processor and resources, allocating what is needed to each
operating system in turn and making sure that the guest operating systems
(called virtual machines) cannot disrupt each other.
Q :
-
What are the products included in VMware vSphere 5.5 Bundle ?
Ans :
-
VMware ESXi
VMware vCenter Server
VMware vSphere Client and Web Client
vSphere Update Manager
VMware vCenter Orchestrator
Q :
-
What are the basic commands to troubleshoot connectivity between
vSphere Client /vCenter to ESX server?
Ans :
-
service mgmt
-
vmware restart (restarts host agent(vmware
-
hostd) on
vmware esx server)
service vmware
-
vpxa restart (restarts Vcenter agent service)
service network restart (restarts management networks on ESX)
Q :
-
What is vCenter Agent?
Ans :
-
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.
Q :
-
What type of Hypervisor VMware ESXi is ?
Ans :
-
VMware ESXi is Bare
-
metal hypervisor. You can directly install on
server hardware.
What is the command used to restart SSH, NTP & Vmware Web access?
Ans :
-
Service sshd restart
Service ntpd restart
Service vmware
-
webaccess restart
Q :
-
What is VMKernel ?
Ans :
-
VMWare Kernel is a Proprietary kernel of vmware and is not based on
any of the flavors of Linux operating systems.
1.
VMkernel requires an operating system to boot and manage the kernel.
2.
A service console is being provided when VMWare kernel is booted.
3.
Only service console is based up on Redhat Linux OS not VMkernel.
What are the types of Ports groups in ESX/ESXi ?
Ans :
-
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 the use of Service Console port ?
Ans :
-
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.
Q :
-
What is the use of VMKernel Port ?
Ans :
-
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.
Q :
-
What is the use of Virtual Machine Port Group?
Ans :
-
Virtual Machine port group is used by Virtual machine communication.
Q :
-
How Virtual Machine communicates to another servers in Network ?
Ans :
-
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.
Q :
-
What is the default number of ports configured with the Virtual Switch?
Ans :
-
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.
Q :
-
What are the different types of Partitions in ESX server?
Ans :
-
/
-
root
Swap
/var
/Var/core
/opt
/home
/tmp
Q :
-
What are the Traffic Shaping policies available in the Vswitch?
Ans :
-
Traffic shaping policies are disabled by default. There are 3 different
traffic shaping policy setting
Average Bandwidth Average Bandwidth is defined in KBPS
Peak Bandwidth Peak bandwidth is defined in KBPS
Burst Size Burst Size is defined in Kilobytes
Q :
-
What are the security options available for ESX vswitch?
Ans :
-
Promiscuous Mode
–
Reject
MAC Address changes
–
Accept
Forged Transmits
–
Accept
Q :
-
What are the types of VLAN tagging in Vsphere?
Ans :
-
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)
Q :
-
What are the Load balancing policies available in vswitch?
Ans :
-
Route based on the originating virtual switch port ID
Route based on source MAC hash
Route based on IP hash
Q :
-
what is the command to get the information about physical nics installed on ESX
server?
Ans :
-
esxcfg
-
vmknic
-
l
Q :
-
What is command to add the new virtual switch named (vswitch3) to our ESX
server?
Ans :
-
esxcfg
-
vswitch
-
a vswitch3
Q :
-
What is command to add the new port group named (mgmt)to vswitch (vswitch 3)
Ans :
-
esxcfg
-
vswitch
-
A mgmt vswitch3
Q :
-
How many ESXi hosts u have in ur organization? Or size of your
infrastructure?
Ans :
-
It depends on your experience or organization, for example I can say
we have 60 ESXi hosts and 10 clusters. It consists of almost 7000 machines.
Administrator needs to access ESXi host through putty by remotely, but he is
not able to access what you will do in this situation?
First, ping the ESXi host IP/hostname. If ping works fine check 22 port is
open or not.
Second, Enable the SSH service from configuration tab, security profile and
start the SSH service
Q :
-
What is the role of VMware vCenter server?
Ans :
-
vCenter provides a centralized management platform and framework for all
ESXi hosts and their respective VMs. vCenter server allows IT administrators to
deploy, manage, monitor, automate, and secure a virtual infrastructure in a centralized
fashion. To help provide scalability , vCenter Server leverages a back
-
end database
(Microsoft SQL Server and Oracle are both supported, among others) that stores all
the data about the hosts and VMs.
Q :
-
Is it possible install vCenter server on Linux hosts ?
Ans :
-
No.But Pre
-
build vCenter appliance is available in VMware portal which is
Linux based.You can import the appliance as virtual machine.
Q :
-
How to update the VMware ESXi hosts with latest patches ?
Ans :
-
We can update the ESXi hosts using VMware Update Manager(VUM). We
can use this VUM add
-
on package on Windows based vCenter server and Linux
based vCenter server (vCenter appliance)
Q :
-
What is the use of VMware vSphere Client and vSphere Web Client ?
Ans :
-
vCenter Server provides a centralized management framework to VMware
ESXi hosts.To access vCenter server, you need vSphere client or vSphere Web client
service enabled.
Q :
-
What is the difference between vSphere Client and vSphere web client ?
Ans :
-
vSphere Client is traditional utility which provides user interface to vCenter
server. But from VMware vSphere 5 onwards,vSphere web client is a primary
interface to manage vCenter server.For vSphere client, you need install small utility
.But vSphere Web client does not require any software. You can directly connect
using web browser.But still VUM is managed through vSphere Client .
Q :
-
What is the use of VMware vCenter Orchestrator ?
Ans :
-
vCenter Orchestrator is used for automation on various vSphere products.
Q :
-
What are the features included in VMware vSphere 5.5 ?
Ans :
-
vSphere High Availability (HA)
vSphere Fault Tolerance
vSphere vMotion
vSphere Storage vMotion
vSphere Distributed Resource Scheduler (DRS)
virtual SAN (VSAN)
Flash Read Cache
Storage I/O Control
Network I/O Control
vSphere Replication
Q :
-
What is the use of vSphere High Availability(HA)? Where it can be applied ?
Ans :
-
VMware vSphere HA minimize the VM’s unplanned downtime by restarting
the VM guests on next available server ESXi node in a case of failure on current ESXI
node. VMware HA must be enabled to reduce the VM unplanned downtime.
Q :
-
What is the hardware version used in VMware ESXi 5.5?
Version 10 ?
Ans :
-
Below is the table showing the different version of hardware used in different VMware
products along with their release version
Virtual Hardware Version
Products
10ESXi 5.5, Fusion 6.x, Workstation 10.x, Player 6.x
9
ESXi 5.1, Fusion 5.x, Workstation 9.x, Player 5.x
8
ESXi 5.0, Fusion 4.x, Workstation 8.x, Player 4.x
7
ESXi/ESX 4.x, Fusion 2.x/3.x Workstation 6.5.x/7.x,Player 3.x
6
Workstation 6.0.x
4
ACE 2.x, ESX 3.x, Fusion 1.x, Player 2.x
3 and 4
ACE 1.x, Player 1.x, Server 1.x, Workstation 5.x, Workstation 4.x
3
ESX 2.x, GSX Server 3.x
Q :
-
What is the difference between the vSphere ESX and ESXi architectures?
Ans :
-
VMware ESX and ESXi are both bare metal hypervisor architectures
that install directly on the server hardware.
Although neither hypervisor architectures relies on an OS for resource
management, the vSphere ESX architecture relied on a Linux operating
system, called the Console OS (COS) or service console, to perform two
management functions: executing scripts and installing third
-
party agents for
hardware monitoring, backup or systems management.
In the vSphere ESXi architecture, the service console has been removed. The
smaller code base of vSphere ESXi represents a smaller “attack surface” and
less code to patch, improving reliability and security.
Q :
-
What is a .vmdk file?
Ans :
-
This isn’t the file containing the raw data. Instead it is the disk
descriptor file which describes the size and geometry of the virtual
disk file. This file is in text format and contains the name of the
–
flat.vmdk file for which it is associated with and also the hard drive
adapter type, drive sectors, heads and cylinders, etc. One of these
files will exist for each virtual hard drive that is assigned to your
virtual machine. You can tell which
–
flat.vmdk file it is associated
with by opening the file and looking at the Extent Description field.
Follow the below link for more details
Q :
-
What are the different types of virtualization?
Ans :
-
Server Virtualization
–
consolidating multiple physical servers into
virtual servers that run on a single physical server.
Application Virtualization
–
an application runs on another host from where it
is installed in a variety of ways. It could be done by application streaming,
desktop virtualization or VDI, or a VM package (like VMware ACE creates
with a player). Microsoft Softgrid is an example of Application virtualization.
Presentation Virtualization
–
This is what Citrix Met frame (and the ICA
protocol) as well as Microsoft Terminal Services (and RDP) are able to create.
With presentation virtualization, an application actually runs on another host
and all that you see on the client is the screen from where it is run.
Network Virtualization
–
with network virtualization, the network is “carved up” and
can be used for multiple purposes such as running a protocol analyzer inside an
Ethernet switch. Components of a virtual network could include NICs, switches,
VLANs, network storage devices, virtual network containers, and network media.
Storage Virtualization
–
with storage virtualization, the disk/data storage for your data
is consolidated to and managed by a virtual storage system. The servers connected to
the storage system aren’t aware of where the data really is. Storage virtualization is
sometimes described as “abstracting the logical storage from the physical storage.
Q :
-
Will vSphere HA help on VM failures too ?
Ans :
-
In an order to detect the VM failures, you need to enable VM Failure
Monitoring. So that it detects the Disk I/O and sends the internal heartbeat to check the
VM all the time. If the VM is stopped functioning, VM will be restarted automatically
by vSphere HA.
Q :
-
What is VMware vMotion and what are its requirements?
Ans :
-
VMware VMotion enables the live migration of running virtual machines
from one physical server to another with zero downtime.
VMotion lets you:
Automatically optimize and allocate entire pools of resources for maximum
hardware utilization and availability.
1.
Perform hardware maintenance without any scheduled downtime.
2.
Proactively migrate virtual machines away from failing or under
performing servers.
3.
Below are the pre
-
requisites for configuring vMotion
Q :
-
What is the difference between clone and template in VMware?
Ans :
-
Clone
1.
A clone is a copy of virtual machine.
2.
You cannot convert back the cloned Virtual Machine.
3.
A Clone of a Virtual Machine can be created when the Virtual Machine is powered on
4.
Cloning can be done in two ways namely Full Clone and Linked Clone.
5.
A full clone is an independent copy of a virtual machine that shares nothing with the parent
virtual machine after the cloning operation.
6.
Ongoing operation of a full clone is entirely separate from the parent virtual machine.
7.
A linked clone is a copy of a virtual machine that shares virtual disks with the parent virtual
machine in an ongoing manner.
8.
This conserves disk space, and allows multiple virtual machines to use the same software
installation.
9.
Cloning a virtual machine can save time if you are deploying many similar virtual
machines.
10.
You can create, configure, and install software on a single virtual machine, and then clone
it multiple times, rather than creating and configuring each virtual machine individually.
Template
1.
A template is a master copy or a baseline image of a virtual machine that can be used to
create many clones.
2.
Templates cannot be powered on or edited, and are more difficult to alter than ordinary
virtual machine.
3.
You can convert the template back to Virtual Machine to update the base template with the
latest released patches and updates and to install or upgrade any software and again convert
back to template to be used for future deployment of Virtual Machines with the latest
patches.
4.
Convert virtual Machine to template cannot be performed, when Virtual machine is
powered on. Only Clone to Template can be performed when the Virtual Machine is
powered on.
5.
A template offers a more secure way of preserving a virtual machine configuration that you
want to deploy many times.
6.
When you clone a virtual machine or deploy a virtual machine from a template, the
resulting cloned virtual machine is independent of the original virtual machine or template.
Q :
-
What is promiscuous mode in Vmware?
Ans :
-
Promiscuous mode is a security policy which can be defined at the
virtual switch or port group level
A virtual machine, Service Console or VMkernel network interface in a
portgroup which allows use of promiscuous mode can see all network traffic
traversing the virtual switch.
If this mode is set to reject, the packets are sent to intended port so that the
intended virtual machine will only be able to see the communication.
Example: In case you are using a virtual xp inside any Windows VM. If
promiscuous mode is set to reject then the virtual xp won’t be able to connect
the network unless promiscuous mode is enabled for the Windows VM.
Q :
-
What is the difference between Thick provision Lazy Zeroed, Thick provision Eager Zeroed
and Thin provision?
Ans :
-
Thick Provision Lazy Zeroed
Creates a virtual disk in a default thick format.
Space required for the virtual disk is allocated when the virtual disk is created.
Data remaining on the physical device is not erased during creation, but is zeroed out on demand
at a later time on first write from the virtual machine.
Using the default flat virtual disk format does not zero out or eliminate the possibility of
recovering deleted files or restoring old data that might be present on this allocated space.
You cannot convert a flat disk to a thin disk.
Thick Provision Eager Zeroed
A type of thick virtual disk that supports clustering features such as Fault Tolerance.
Space required for the virtual disk is allocated at creation time.
In contrast to the flat format, the data remaining on the physical device is zeroed out when the
virtual disk is created.
It might take much longer to create disks in this format than to create other types of disks.
Thin Provision
It provides on on
-
demand allocation of blocks of data.
All the space allocated at the time of creation of virtual disk is not utilized on the hard
disk, rather only the size with utilized data is locked and the size increases as the
amount of data is increased on the disk.
With thin provisioning, storage capacity utilization efficiency can be automatically
driven up towards 100% with very little administrative overhead.
Q :
-
How you configure in time in ESXi host?
Ans :
-
GUI and configuration NTP server
Can you explain Difference between physical and virtual switch?
Virtual switch works like physical switch only but it’s not configurable.
Q :
-
What is a snapshot?
Ans :
-
A snapshot is a “point in time image” of a virtual guest operating
system (VM). That snapshot contains an image of the VMs disk, RAM, and
devices at the time the snapshot was taken. With the snapshot, you can return
the VM to that point in time, whenever you choose. You can take snapshots of
your VMs, no matter what guest OS you have and the snapshot functionality
can be used for features like performing image level backups of the VMs
without ever shutting them down.
Q :
-
How can you go to BIOS setting for VM?
Ans :
-
We have to select Boot Options Force BIOS Setup from Virtual
machine settings. When you restart the machine it will take into the BIOS
settings.
Q :
-
What is VDI?
Ans :
-
VDI stands for Virtual Desktop Infrastructure where end user physical machine
like desktop or laptop are virtualized due to which VMware described VDI as
“delivering desktops from the data center”.
Once VDI is used the end user connect to their desktop using a device called thin
client.
The end user can also connect to their desktop using VMware Horizon View installed
on any desktop or mobile devices.
Q :
-
Explain about HA process?
Ans :
-
Selection of Master
-
slave servers
Q :
-
What is the Agent used in HA?
Ans :
-
FDM
-
Fault Domain Manager
Q :
-
What is VMware HA?
Ans :
-
VMware HA i.e. High Availability which works on the host level and is configured on
the Cluster.
A Cluster configured with HA will migrate and restart all the vms running under any of the host
in case of any host
-
level failure automatically to another host under the same cluster.
VMware HA continuously monitors all ESX Server hosts in a cluster and detects failures.
VMware HA agent placed on each host maintains a heartbeat with the other hosts in the cluster
using the service console network. Each server sends heartbeats to the others servers in the
cluster at five
-
second intervals. If any servers lose heartbeat over three consecutive heartbeat
intervals, VMware HA initiates the failover action of restarting all affected virtual machines on
other hosts.
You can set virtual machine restart priority in case of any host failure depending upon the critical
nature of the vm.
NOTE: Using HA in case of any host failure with RESTART the vms on different host so the
vms state will be interrupted and it is not a live migration
Q :
-
What is the difference between VMware HA and vMotion?
Ans :
-
VMware HA is used in the event when any of the hosts inside
a cluster fails then all the virtual machines running under it are
restarted on different host in the same cluster.
Now HA is completely dependent on vMotion to migrate the vms to
different host so vMotion is just used for the migration purpose
between multiple hosts. vMotion also has the capability to migrate
any vm without interrupting its state to any of the host inside cluster.
Q :
-
What is storage vMotion?
Ans :
-
Storage vMotion is similar to vMotion in the sense that “something” related to the
VM is moved and there is no downtime to the VM guest and end users. However, with
SVMotion the VM Guest stays on the server that it resides on but the virtual disk for that
VM is what moves.
With Storage vMotion, you can migrate a virtual machine and its disk files from one
datastore to another while the virtual machine is running.
You can choose to place the virtual machine and all its disks in a single location, or select
separate locations for the virtual machine configuration file and each virtual disk.
During a migration with Storage vMotion, you can transform virtual disks from Thick
-
Provisioned Lazy Zeroed or Thick
-
Provisioned Eager Zeroed to Thin
-
Provisioned or the
reverse.
Perform live migration of virtual machine disk files across any Fibre Channel, iSCSI, FCoE
and NFS storage
Q :
-
What is VMware DRS and how does it works?
Ans :
-
Here DRS stands for Distributed Resource Scheduler which dynamically balances
resource across various host under Cluster or resource pool.
VMware DRS allows users to define the rules and policies that decide how virtual machines
share resources and how these resources are prioritized among multiple virtual machines.
Resources are allocated to the virtual machine by either migrating it to another server with more
available resources or by making more “space” for it on the same server by migrating other
virtual machines to different servers.
The live migration of virtual machines to different physical servers is executed completely
transparent to end
-
users through VMware VMotion
VMware DRS can be configured to operate in either automatic or manual mode. In automatic
mode, VMware DRS determines the best possible distribution of virtual machines among
different physical servers and automatically migrates virtual machines to the most appropriate
physical servers. In manual mode, VMware DRS provides a recommendation for optimal
placement of virtual machines, and leaves it to the system administrator to decide whether to
make the change.
Q :
-
What is VMware Fault Tolerance?
Ans :
-
VMware Fault Tolerance provides continuous availability to applications
running in a virtual machine, preventing downtime and data loss in the event of server
failures.
VMware Fault Tolerance, when enabled for a virtual machine, creates a live shadow
instance of the primary, running on another physical server.
The two instances are kept in virtual lockstep with each other using VMware
vLockstep technology
The two virtual machines play the exact same set of events, because they get the exact
same set of inputs at any given time.
The two virtual machines constantly heartbeat against each other and if either virtual
machine instance loses the heartbeat, the other takes over immediately. The heartbeats
are very frequent, with millisecond intervals, making the failover instantaneous with no
loss of data or state.
VMware Fault Tolerance requires a dedicated network connection, separate from the
VMware VMotion network, between the two physical servers.
Q :
-
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?
Ans :
-
You can place the original (or Primary virtual machine). You have full
control with DRS or vMotion to assign it to any node. The placement of the
Secondary, when created, is automatic based on the available hosts. But when
the Secondary is created and placed, you can vMotion it to the preferred host.
Q :
-
How many virtual CPUs can I use on a Fault Tolerant virtual machine ?
Ans :
-
vCenter Server 4.x and vCenter Server 5.x support 1 virtual CPU per
protected virtual machine.
Q :
-
What is the difference between Type 1 and Type 2 Hypervisor?
Ans :
-
Type 1 Hypervisor
This is also known as Bare Metal or Embedded or Native Hypervisor.
It works directly on the hardware of the host and can monitor operating
systems that run above the hypervisor.
It is completely independent from the Operating System.
The hypervisor is small as its main task is sharing and managing hardware
resources between different operating systems.
A major advantage is that any problems in one virtual machine or guest
operating system do not affect the other guest operating systems running on the
hypervisor.
Examples: VMware ESXi Server, Microsoft Hyper
-
V, Citrix/XenServer.
Type 2 Hypervisor
This is also known as Hosted Hypervisor.
In this case, the hypervisor is installed on an operating system and
then supports other operating systems above it.
It is completely dependent on host Operating System for its
operations
While having a base operating system allows better specification of
policies, any problems in the base operating system affects the entire
system as well even if the hypervisor running above the base OS is
secure.
Examples: VMware Workstation, Microsoft Virtual PC, Oracle
Virtual Box
Q :
-
How does vSphere HA works?
Ans :
-
When we configure multiple hosts for HA cluster, a single host is
automatically elected as the master host. The master host communicates with
vCenter Server and monitors the state of all protected virtual machines and of
the slave hosts. When you add a host to a vSphere HA cluster, an agent is
uploaded to the host and configured to communicate with other agents in the
cluster.
Q :
-
What are the monitoring methods used for vSphere HA?
Ans :
-
The Master and Slave hosts uses two types of monitoring the status of
the hosts
Datastore Heartbeat
Network Heartbeat
Q :
-
What are the roles of master host in vSphere HA?
Ans :
-
Monitoring the state of slave hosts. If a slave host fails or
becomes unreachable, the master host identifies which virtual
machines need to be restarted.
Monitoring the power state of all protected virtual machines. If one
virtual machine fails, the master host ensures that it is restarted.
Using a local placement engine, the master host also determines
where the restart should be done.
Managing the lists of cluster hosts and protected virtual machines.
Acting as vCenter Server management interface to the cluster and
reporting the cluster health state.
Q :
-
How is a Master host elected in vSphere HA environment?
Ans :
-
When vSphere HA is enabled for a cluster, all active hosts
(those not in standby or maintenance mode, or not disconnected)
participate in an election to choose the cluster’s master host. The host
that mounts the greatest number of datastores has an advantage in the
election. Only one master host typically exists per cluster and all
other hosts are slave hosts.
If the master host fails, is shut down or put in standby mode, or is
removed from the cluster a new election is held.
Q :
-
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?
Ans :
-
vSphere HA is not dependent on vCenterserver for its operations as when HA is
configured it installs an agent into each host which does its part and is not dependent on
vCenterserver. Also HA doesnot uses vMotion, it justs restarts the vms into another host in any
case of host failure.
Further vSphere DRS is very much dependent on vCenterserver as it uses vMotion for its action
for live migration of vms between multiple hosts so in case vCenterserver goes down the
vMotion won’t work leading to failure of DRS.
Q :
-
What is the use of vmware tools?
Ans :
-
VMware Tools is a suite of utilities that enhances the performance of the virtual
machine's guest operating system and improves management of the virtual machine.
Without VMware Tools installed in your guest operating system, guest performance
lacks important functionality. Installing VMware Tools eliminates or improves these
issues:
Low video resolution
Inadequate color depth
Incorrect display of network speed
Restricted movement of the mouse
Inability to copy and paste and drag
-
and
-
drop files
Missing sound
Provides the ability to take quiesced snapshots of the guest OS
Synchronizes the time in the guest operating system with the time on the host
Provides support for guest
-
bound calls created with the VMware VIX API
Q :
-
What is the use of Storage vMotion ?
Ans :
-
vMotion is possible only when you have Shared storage like
FC
-
SAN,ISCSI
-
SAN or NFS. If you want to move the VM from one
datastore to another datastore without any downtime,then you need to
perform storage vMotion.
Q :
-
What is the use of vMotion ?
Ans :
-
Using vMotion feature,we can move the running VM’s from
one ESXi host to another ESXi host without any downtime. vMotion
copies the VM’s in
-
memory contents to the destination server and
freeze the operation on current ESXi host and resumes the VM’s on
remote ESXI node.
Q :
-
Why vMotion feature is not used/can’t use in vSphere HA ?
Ans :
-
vMotion is used for planned migrations and possible only where
the source and destination ESXI hosts are running properly.vSPhere HA
is used to reduce the downtime due to failures of physical ESXi hosts.So
When the failure accours on ESXi nodes, there is no time to perform
vMotion and can’t be used.
Q :
-
Is there any way to prevent the VM’s unplanned downtime using
vSphere HA ?
Ans :
-
Yes.You can prevent the unplanned downtime using vSphere fault
tolerance along with vSphere HA.
Q :
-
How the vSphere Fault tolerance(FT) works ?
Ans :
-
Using vLockstep technology , vSphere FT maintains the mirrored secondary VM on
different ESXi physical host that is kept in lockstep with the primary.So when the primary ESXi
node goes down due to hardware issue, secondary VM will immediately step
-
in and provide the
service. At this point, this VM will become primary and secondary aka mirrored VM will be
created on possible ESXI host to prevent the further ESXi failure.
Q :
-
What is vSphere DRS(Distributed Resource Scheduler) ? How it works ?
Ans :
-
vSphere DRS is an intelligent frameworks which always monitors the
cluster nodes health check and performs the vMotion automatically whenever
required. For an example ,if one of the ESXI cluster host memory has been
utilized more than 90% and due to that lot of paging happening on that server.
vSphere DRS detects such things in quick time and moves few VM’s to
another ESXi cluster to least
-
balance the cluster nodes without any downtime
by leveraging vMotion functionality. It applies for high contention for CPU
utilization too. So vSphere DRS helps to balance the CPU & Memory
utilization across the ESXi cluster nodes.
Q :
-
What is vSphere storage DRS ? How it works ?
Ans :
-
vSphere Storage DRS like vSphere DRS but it applies to storage.It
helps to balance storage utilization and performance between data
-
stores on
same ESXi clusters.
Q :
-
What is VSAN ? How it works ?
Ans :
-
VSAN forms the storage pools across the multiple nodes using internal disks and allows
you to create a datastores that spans multiple ESXI hosts. VSAN also protect the data using VM
storage profiles and you can configure it according to your requirement. You need SSD’s(Solid
State Drive) to configure VSAN.
Q :
-
What is Flash Read Cache ?
Ans :
-
vSphere 5.5 supports solid state drive through feature called Flash Read Cache.Using
Flash Read Cache, you can assign a caching space to VM’s like how are you assigning like
CPU,Memory and other resources to VM’s. Solid state drive can provide much better that IOPS
compare to normal disks.
Q :
-
What happens if vCenter Server is offline when a failover event occurs?
Ans :
-
When Fault Tolerance is configured for a virtual machine, vCenter Server need not be
online for FT to work. Even if vCenter Server is offline, failover still occurs from the Primary to
the Secondary virtual machine. Additionally, the spawning of a new Secondary virtual machine
also occurs without vCenter Server.
Q :
-
What is Service Console?
Ans :
-
The service console is developed based up on Redhat Linux Operating system, it is used
to manage the VMKernel
Q :
-
What is the use of Storage I/O Control in vSphere 5.5 ?
Ans :
-
You can limit the number of IOPS for each VM.
Q :
-
What is the use of network I/O control ?
Ans :
-
Its similar to storage I/O control but its controls the VM’s Network bandwidth.
Q :
-
What is vSphere Replication?
Ans :
-
It replicates the complete VM from one datacenter to another datacenter on per VM basis
Unlike hardware replication.
Q :
-
HA works without vCenter?
Ans :
-
Yes, because of HA will works by using master and slave relationship in cluster. ESXi
hosts is sending/receiving heartbeats by using fdm agent.
Q :
-
Can DRS works without vCenter?
Ans :
-
Ans is No because DRS is managed by vCenter
Q :
-
What is the critical issue you resolved?
Ans :
-
It depends on how much you have expertise on particular module. Explain one scenario
which discussed in the classes.
Q :
-
What are the three port groups present in ESX server networking
Ans :
-
1. Virtual Machine Port Group
-
Used for Virtual Machine Network
2. Service Console Port Group
-
Used for Service Console Communications
3. VMKernel Port Group
-
Used for VMotion, iSCSI, NFS Communications
Q :
-
What are the files that make a Virtual Machine ?
Ans :
-
.vmx
-
Virtual Machine Configuration File
.nvram
-
Virtual Machine BIOS
.vmdk
-
Virtual Machine Disk file
.vswp
-
Virtual Machine Swap File
.vmsd
-
Virtual MAchine Snapshot Database
.vmsn
-
Virtual Machine Snapshot file
.vmss
-
Virtual Machine Suspended State file
.vmware.log
-
Current Log File
.vmware
-
#.log
-
Old Log file
Q3) What is the difference between the vSphere ESX and ESXi architectures?
VMware ESX and ESXi are both bare metal hypervisor architectures that install directly on the server hardware.
Although neither hypervisor architectures relies on an OS for resource management, the vSphere ESX architecture relied on a Linux operating system, called the Console OS (COS) or service console, to perform two management functions: executing scripts and installing third-party agents for hardware monitoring, backup or systems management.
In the vSphere ESXi architecture, the service console has been removed. The smaller code base of vSphere ESXi represents a smaller “attack surface” and less code to patch, improving reliability and security.
Q4) What is a .vmdk file?
This isn’t the file containing the raw data. Instead it is the disk descriptor file which describes the size and geometry of the virtual disk file. This file is in text format and contains the name of the –flat.vmdk file for which it is associated with and also the hard drive adapter type, drive sectors, heads and cylinders, etc. One of these files will exist for each virtual hard drive that is assigned to your virtual machine. You can tell which –flat.vmdk file it is associated with by opening the file and looking at the Extent Description field.
Q5). What are the different types of virtualization?
Server Virtualization – consolidating multiple physical servers into virtual servers that run on a single physical server.
Application Virtualization – an application runs on another host from where it is installed in a variety of ways. It could be done by application streaming, desktop virtualization or VDI, or a VM package (like VMware ACE creates with a player). Microsoft Softgrid is an example of Application virtualization.
Presentation Virtualization – This is what Citrix Met frame (and the ICA protocol) as well as Microsoft Terminal Services (and RDP) are able to create. With presentation virtualization, an application actually runs on another host and all that you see on the client is the screen from where it is run.
Network Virtualization – with network virtualization, the network is “carved up” and can be used for multiple purposes such as running a protocol analyzer inside an Ethernet switch. Components of a virtual network could include NICs, switches, VLANs, network storage devices, virtual network containers, and network media.
Storage Virtualization – with storage virtualization, the disk/data storage for your data is consolidated to and managed by a virtual storage system. The servers connected to the storage system aren’t aware of where the data really is. Storage virtualization is sometimes described as “abstracting the logical storage from the physical storage.
Q6) What is VMware vMotion and what are its requirements?
VMware VMotion enables the live migration of running virtual machines from one physical server to another with zero downtime.
VMotion lets you:
1. Automatically optimize and allocate entire pools of resources for maximum hardware utilization and
2. Perform hardware maintenance without any scheduled downtime.
3. Proactively migrate virtual machines away from failing or underperforming servers.
Below are the pre-requisites for configuring vMotion
1. Each host must be correctly licensed for vMotion
2. Each host must meet shared storage requirements
3. vMotion migrates the vm from one host to another which is only possible with both the host are sharing a common storage or to any storage accessible by both the source and target hosts.
4. A shared storage can be on a Fibre Channel storage area network (SAN), or can be implemented using iSCSI SAN and NAS.
5. If you use vMotion to migrate virtual machines with raw device mapping (RDM) files, make sure to maintain consistent LUN IDs for RDMs across all participating hosts.
6. Each host must meet the networking requirements
7. Configure a VMkernel port on each host.
8. Dedicate at least one GigE adapter for vMotion.
9. Use at least one 10 GigE adapter if you migrate workloads that have many memory operations.
10. Use jumbo frames for best vMotion performance.
11. Ensure that jumbo frames are enabled on all network devices that are on the vMotion path including physical NICs, physical switches and virtual switches.
Q7) Clone Vs Template in VMware?
Clone: A Copy of virtual machine
-> Can't be restore the cloned Virtual Machine.
-> Clone of an Virtual Machine also be created while the Virtual Machine is switched on
-> Cloning can be done in two ways namely Full Clone and Linked Clone.
-> A full type clone is an independent copy of a virtual machine that shares nothing with the parent virtual machine after the cloning operation. Ongoing operation of a full clone is entirely separate from the parent virtual machine.
-> A linked clone is a copy of a virtual machine that shares virtual disks with the parent virtual machine in an ongoing manner. This conserves disk space, and allows multiple virtual machines to use the same software installation.
-> Cloning a virtual machine can save time if you are deploying many similar virtual machines. You can create, configure, and install software on a single virtual machine, and then clone it multiple times, rather than creating and configuring each virtual machine individually.
Template - A master copy or a baseline image of an virtual machine that shall be used to create many clones.
-> Templates cannot be powered on or edited, and are more difficult to alter than ordinary virtual machine.
-> You can convert the template back to Virtual Machine inorder to update the base template with the latest released patches and updates and to install or upgrade any software and again convert back to template to be used for future deployment of Virtual Machines with the latest patches.
-> Convert virtual Machine to template can't be performed, when Virtual machine is powered on. Only Clone to Template can be performed when the Virtual Machine is powered on.
-> A template offers a more secure way of preserving a virtual machine configuration that you want to deploy many times.
-> While you are cloning a virtual machine or deploying a virtual machine by a template, resulting cloned virtual machine will be an independent of the original template or virtual machine.
Q8) What is a promiscuous mode in Vmware?
1. Promiscuous mode is a security policy which can be defined at the virtual switch or portgroup level
2. A virtual machine, Service Console or VMkernel network interface in a portgroup which allows use of promiscuous mode can see all network traffic traversing the virtual switch.
3.I f this mode is set to reject, the packets are sent to intended port so that the intended virtual machine will only be able to see the communication.
4. Example: In case you are using a virtual xp inside any Windows VM. If promiscuous mode is set to reject then the virtual xp won’t be able to connect the network unless promiscuous mode is enabled for the Windows VM.
Q9). What is the difference between Thick provision Lazy Zeroed, Thick provision Eager Zeroed and Thin provision?
Thick Provision Lazy Zeroed
1. Creates a virtual disk in a default thick format.
2. Space required for the virtual disk is allocated when the virtual disk is created.
3. Data remaining on the physical device is not erased during creation, but is zeroed out on demand at a later time on first write from the virtual machine.
4. Using the default flat virtual disk format does not zero out or eliminate the possibility of recovering deleted files or restoring old data that might be present on this allocated space.
5. You cannot convert a flat disk to a thin disk.
Thick Provision Eager Zeroed
1. A type of thick virtual disk that supports clustering features such as Fault Tolerance.
2. Space required for the virtual disk is allocated at creation time.
3. In contrast to the flat format, the data remaining on the physical device is zeroed out when the virtual disk is created.
4. It might take much longer to create disks in this format than to create other types of disks.
Thin Provision
1. It provides on on-demand allocation of blocks of data.
2. All the space allocated at the time of creation of virtual disk is not utilized on the hard disk, rather only the size with utilized data is locked and the size increases as the amount of data is increased on the disk.
3. With thin provisioning, storage capacity utilization efficiency can be automatically driven up towards 100% with very little administrative overhead.
Q10) What is a snapshot?
A snapshot is a “point in time image” of a virtual guest operating system (VM). That snapshot contains an image of the VMs disk, RAM, and devices at the time the snapshot was taken. With the snapshot, you can return the VM to that point in time, whenever you choose. You can take snapshots of your VMs, no matter what guest OS you have and the snapshot functionality can be used for features like performing image level backups of the VMs without ever shutting them down.
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Q11) What is VDI?
1. VDI stands for Virtual Desktop Infrastructure where end user physical machine like desktop or laptop are virtualized due to which VMware described VDI as “delivering desktops from the data center”.
2. Once VDI is used the end user connect to their desktop using a device called thin client.
3. The end user can also connect to their desktop using VMware Horizon View installed on any desktop or mobile devices
Q12) What is VMware HA?
1. VMware HA i.e. High Availability which works on the host level and is configured on the Cluster.
2. A Cluster configured with HA will migrate and restart all the vms running under any of the host in case of any host-level failure automatically to another host under the same cluster.
3. VMware HA continuously monitors all ESX Server hosts in a cluster and detects failures.
4. VMware HA agent placed on each host maintains a heartbeat with the other hosts in the cluster using the service console network. Each server sends heartbeats to the others servers in the cluster at five-second intervals. If any servers lose heartbeat over three consecutive heartbeat intervals, 5.VMware HA initiates the failover action of restarting all affected virtual machines on other hosts.
You can set virtual machine restart priority in case of any host failure depending upon the critical nature of the vm.
NOTE: Using HA in case of any host failure with RESTART the vms on different host so the vms state will be interrupted and it is not a live migration
Q13) What is the difference between VMware HA and vMotion?
VMware HA is used in the event when any of the hosts inside a cluster fails then all the virtual machines running under it are restarted on different host in the same cluster.
Now HA is completely dependent on vMotion to migrate the vms to different host so vMotion is just used for the migration purpose between multiple hosts. vMotion also has the capability to migrate any vm without interrupting its state to any of the host inside cluster.
Q14) What is storage vMotion?
1. Storage vMotion is similar to vMotion in the sense that “something” related to the VM is moved and there is no downtime to the VM guest and end users. However, with SVMotion the VM Guest stays on the server that it resides on but the virtual disk for that VM is what moves.
2. With Storage vMotion, you can migrate a virtual machine and its disk files from one datastore to another while the virtual machine is running.
3. You can choose to place the virtual machine and all its disks in a single location, or select separate locations for the virtual machine configuration file and each virtual disk.
4. During a migration with Storage vMotion, you can transform virtual disks from Thick-Provisioned Lazy Zeroed or Thick-Provisioned Eager Zeroed to Thin-Provisioned or the reverse.
5. Perform live migration of virtual machine disk files across any Fibre Channel, iSCSI, FCoE and NFS storage
Q15) What is VMware DRS and how does it works?
1. Here DRS stands for Distributed Resource Scheduler which dynamically balances resource across various host under Cluster or resource pool.
2. VMware DRS allows users to define the rules and policies that decide how virtual machines share resources and how these resources are prioritized among multiple virtual machines.
3. Resources are allocated to the virtual machine by either migrating it to another server with more available resources or by making more “space” for it on the same server by migrating other virtual machines to different servers.
4. The live migration of virtual machines to different physical servers is executed completely transparent to end-users through VMware VMotion
5. VMware DRS can be configured to operate in either automatic or manual mode. In automatic mode, VMware DRS determines the best possible distribution of virtual machines among different physical servers and automatically migrates virtual machines to the most appropriate physical servers. In manual mode, VMware DRS provides a recommendation for optimal placement of virtual machines, and leaves it to the system administrator to decide whether to make the change.
Q16) What is VMware Fault Tolerance?
1. VMware Fault Tolerance provides continuous availability to applications running in a virtual machine, preventing downtime and data loss in the event of server failures.
2. VMware Fault Tolerance, when enabled for a virtual machine, creates a live shadow instance of the primary, running on another physical server.
3. The two instances are kept in virtual lockstep with each other using VMware vLockstep technology
4. The two virtual machines play the exact same set of events, because they get the exact same set of inputs at any given time.
5. The two virtual machines constantly heartbeat against each other and if either virtual machine instance loses the heartbeat, the other takes over immediately. The heartbeats are very frequent, with millisecond intervals, making the failover instantaneous with no loss of data or state.
6. VMware Fault Tolerance requires a dedicated network connection, separate from the VMware VMotion network, between the two physical servers.
Q17) 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?
You can place the original (or Primary virtual machine). You have full control with DRS or vMotion to assign it to any node. The placement of the Secondary, when created, is automatic based on the available hosts. But when the Secondary is created and placed, you can vMotion it to the preferred host.
Q18) How many virtual CPUs can I use on a Fault Tolerant virtual machine ?
vCenter Server 4.x and vCenter Server 5.x support 1 virtual CPU per protected virtual machine.
Q19) What happens if vCenter Server is offline when a failover event occurs?
When Fault Tolerance is configured for a virtual machine, vCenter Server need not be online for FT to work. Even if vCenter Server is offline, failover still occurs from the Primary to the Secondary virtual machine. Additionally, the spawning of a new Secondary virtual machine also occurs without vCenter Server.
Q20) What is the difference between Type 1 and Type 2 Hypervisor?
Type 1 Hypervisor
1. This is also known as Bare Metal or Embedded or Native Hypervisor.
2. It works directly on the hardware of the host and can monitor operating systems that run above the hypervisor.
3. It is completely independent from the Operating System.
4. The hypervisor is small as its main task is sharing and managing hardware resources between different operating systems.
5. A major advantage is that any problems in one virtual machine or guest operating system do not affect the other guest operating systems running on the hypervisor.
6. Examples: VMware ESXi Server, Microsoft Hyper-V, Citrix/Xen Server
Type 2 Hypervisor
1. This is also known as Hosted Hypervisor.
2. In this case, the hypervisor is installed on an operating system and then supports other operating systems above it.
3. It is completely dependent on host Operating System for its operations
4. While having a base operating system allows better specification of policies, any problems in the base operating system a ffects the entire system as well even if the hypervisor running above the base OS is secure.
5. Examples: VMware Workstation, Microsoft Virtual PC, Oracle Virtual Box
Q21) How does vSphere HA works?
When we configure multiple hosts for HA cluster, a single host is automatically elected as the master host. The master host communicates with vCenter Server and monitors the state of all protected virtual machines and of the slave hosts. When you add a host to a vSphere HA cluster, an agent is uploaded to the host and configured to communicate with other agents in the cluster.
Q. What are the monitoring methods used for vSphere HA?
The Master and Slave hosts uses two types of monitoring the status of the hosts
1. Datastore Heartbeat
2. Network Heartbeat
Q22) What are the roles of a master host in vSphere HA?
1. Monitoring the state of slave hosts. If a slave host fails or becomes unreachable, the master host identifies which virtual machines need to be restarted.
2. Monitoring the power state of all protected virtual machines. If one virtual machine fails, the master host ensures that it is restarted. Using a local placement engine, the master host also determines where the restart should be done.
3. Managing the lists of cluster hosts and protected virtual machines.
4. Acting as vCenter Server management interface to the cluster and reporting the cluster health state.
Q23) How is a Master host elected in vSphere HA environment?
When vSphere HA is enabled for a cluster, all active hosts (those not in standby or maintenance mode, or not disconnected) participate in an election to choose the cluster’s master host. The host that mounts the greatest number of datastores has an advantage in the election. Only one master host typically exists per cluster and all other hosts are slave hosts.
If the master host fails, is shut down or put in standby mode, or is removed from the cluster a new election is held.
Q24) If the vCenterserver 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?
vSphere HA is not dependent on vCenterserver for its operations as when HA is configured it installs an agent into each host which does its part and is not dependent on vCenterserver. Also HA doesnot uses vMotion, it justs restarts the vms into another host in any case of host failure.
Further vSphere DRS is very much dependent on vCenterserver as it uses vMotion for its action for live migration of vms between multiple hosts so in case vCenterserver goes down the vMotion won’t work leading to failure of DRS.
Q25) What is the use of vmware tools?
VMware Tools is a suite of utilities that enhances the performance of the virtual machine’s guest operating system and improves management of the virtual machine. Without VMware Tools installed in your guest operating system, guest performance lacks important functionality. Installing VMware Tools eliminates or improves these issues:
1. Low video resolution
2. Inadequate color depth
3. Incorrect display of network speed
4. Restricted movement of the mouse
5. Inability to copy and paste and drag-and-drop files
6. Missing sound
7. Provides the ability to take quiesced snapshots of the guest OS
8. Synchronizes the time in the guest operating system with the time on the host
9. Provides support for guest-bound calls created with the VMware VIX AP
Essential:
Engineer the rollout and set the technical standards for the VMware virtual farm based on vSphere ESX, vSAN, vRealize Automation etc for small, medium and large sized data centres.
Propose & evaluate the technical designs and create low level architecture / security standards to support bank’s virtualisation platform.
Participate in VMware architecture reviews and engage stakeholders in the bank to realize the adoption of new architecture standards.
Should be an SME in VMware with at least 8+ years of working experience in the Virtualization domain. Experience on x86 Servers and Blades, Software defined storage / Network / Backup and very good understanding on security standards, Risk & compliance will be an added advantage.
Advance the bank’s private cloud and Iaas Journey by engineering a software defined cloud infrastructure solution that integrate with existing VMware estate to offer a single pane self-service infrastructure management model.
Automate the build, delivery and support of enterprise virtualisation services using Python, Javascript and Powershell.
Engineer and design a global monitoring, log filtering and advanced proactive warning system to effectively manage the virtualisation infrastructure across the bank.
Engineer and automate the low-level security standards across the bank to ensure all the internal cloud components are compliance with the bank’s security standards.
In-depth technical knowledge of VMWare / Virtualisation product suite and technologies.
Strong experience in building highly automated and self-service IAAS platform on the VMware suite of software.
In depth knowledge of hyper converged platform / storage. Preferably VXRACK and VXRail solutions.
Experience in creating automated dashboards for capacity management on virtual environments.
Provide subject matter expertise in tuning and configuration of virtual environments.
Automate the end to end delivery and management of Virtual Infra and accelerate application deployment and releases.
Advanced trouble shooting skills and ability to collaborate with other Infrastructure teams to resolve issues
Working knowledge of Cisco SDN, vSAN, Metro cluster.
Continually improve the Virtual Infrastructure’s support tools and practices whilst maintaining a reliable, cost effective and performant environment.
Ensure highest levels of ownership, accountability and service are maintained within the team.
Ensure Operational process and procedures are formally documented, maintained and adhered to.
Experience in banking industry and Project Management
