VMWARE WINDOWS
Windows 2003 vs Windows 2008
RODC
WDS instead of RIS
Services have been changed as roles - server manager
Introduction of hyper V- only on 64 bit versions
Enhanced event viewer
Bitlocker feature
Server core installation without GUI
MMC 3.0, with three pane view
Key management services(KMS) to activate Windows OS without connecting to Microsoft site
Performance enhancement using technologies like Windows SuperFetch,ReadyBoost and Readydrive
Windows Aero user interface
Instant search
Support for IPv6 in DNS
ESX vs ESXi
ESXi has no service console which is a modified version of RHEL
ESXi is extremely thin hence results in fast installation + fast boot
ESXi can be purchased as an embedded hypervisor on hardware
ESXi has builtin server health status check
ESXi 4.1 vs ESXi 5.0 - Migration
Local upgrade from CD
VMware update manager (only supports upgrade of ESX/ESXi 4.x to ESXi 5.0)
ESXi 4.1 vs ESXi 5.0 - Features
vSphere Auto deploy
Storage DRS
HA - Primary/secondary concept changed to master/slave
Profile driven storage
VMFS version - 3 → 5
ESXi firewall
VMware hardware version - 7 → 8
VMware tools version - 4.1 → 5
vCPU - 8 → 32
vRAM - 256 → 1 TB
VMs per host - 320 → 512
RAM per host - 1TB → 2TB
USB 3.0 support
vApp
FSMO roles
Schema Master
Domain naming master
Infrastructure master
PDC Emulator
RID master
GPO
GPO
Templates (ADMX)
Block inheritance
Enforced
Loopback policy
Forest and Domain concepts
OSI layer
Application Layer
Presentation Layer
Sessions Layer
Transport Layer
Network Layer
DataLink layer
Physical Layer
ASA - site to site VPN
HA 5.0
Uses an agent called FDM - Fault domain manager
HA now talks directly to hostd instead of using vcenter agent vpxa
Master/slave concept
Master
monitors availability of hosts/VMs
manages VM restarts after host failure
maintains list of all VMs in each host
restarting failed VMs
exchanging state with vcenter
monitor state of slaves
Slave
monitor running VMs and send status to master and performs restart on request from master
monitors master node health
if master fails, participates in election
Two different heartbeat mechanisms - Network heartbeat and datastore heartbeat
Network heartbeat
Sends between slave and master per second
When slave is not receiving heartbeat from master, checks whether it is isolated or master is isolated or has failed
Datastore heartbeat
To distinct between isolation and failure
Uses ‘Power On’ file in datastore to determine isolation
This mechanism is used only when master loses network connectivity with hosts
2 datastores are chosen for this purpose
Isolation response
PowerOff
Leave Powered On
Shutdown
vMotion
vMotion enables live migration of running virtual machines from one host to another with zero downtime
Prerequisites
Host must be licensed for vMotion
Configure host with at least one vMotion n/w interface (vmkernel port group)
Shared storage (this has been compromised in 5.1)
Same VLAN and VLAN label
GigaBit ethernet network required between hosts
Processor compatibility between hosts
vMotion does not support migration of applications clustered using Microsoft clustering service
No CD ROM attached
No affinity is enabled
vmware tools should be installed
RAID
Redundant Array of Independent disks
A category of disk drives that uses 2 or more drives in a combination for redundancy and performance
Most common RAIDs: RAID 0(Striped), RAID 1(Mirroring), RAID 5
Backup types
Backup types
Full backup - Will take the backup of all selected files and reset the archive bit
Copy backup - Will take the backup of all selected files but does not reset the archive bit
Incremental backup - Will take the backup of files whose archive bits are set and resets it after backup
Differential backup - Will take the backup of files whose archive bits are set but does not reset it after backup
2003 → 2008 migration
Can be done only by logging in to Windows 2003 server
Min of Windows 2003 SP1 required
Can be migrated only to same version, except for Windows server 2003 standard which can be migrated to either standard or
enterprise
Extra space of 30 GB required prior migration
Cannot upgrade to server core
Perform forestprep and domainprep to 2008 using 2008 cd before migrating. (Copy sources/adprep folder for this)
ESXi update manager
Global Catalog
Global catalog (GC) is a role handled by domain controllers in an Active directory model.
The global catalog stores a full copy of all objects in the directory for its host domain and a partial copy of all objects for all other
domains in the forest.
‘Partial copy’ refers to the set of attributes that are most used for searching every object in every domain.
All domain controllers can be promoted as a GC.
GC helps in faster search of AD objects.
The replicas that are replicated to the global catalog also include the access permissions for each object and attribute.
If you are searching for an object that you do not have permission to access, you do not see the object in the list of search
results. Users can find only objects to which they are allowed access.
Global catalog server clients depend on DNS to provide the IP address of global catalog servers. DNS is required to advertise
global catalog servers for domain controller location.
By default, first DC of in a forest will be a global catalog server
Basic networking concepts
RODC
New feature in Windows 2008
Only have the read only copy of directory database
RODC will have all the objects of a normal DC in read only mode. But this doesn’t include passwords. RODC does not store
password of accounts.
Updates are replicated to RODC by writable DC
Password caching : A feature which enables RODC to cache password of the logged in users.
Password Replication Policy: Determines whether the password can be cached or not.
DNS can be integrated with RODC but will not directly register client updates. For any DNS change, the RODC refers the client
to DNS server that hosts a primary or AD integrated zone
NAS vs SAN
Both used as storage solution
NAS can be used by any device connected using LAN whereas SAN is used only by server class devices with SCSI
NAS is file based whereas SAN is block based storage
NAS is cheap while SAN is expensive
SAN is comparatively faster than NAS
What is DRS? Types of DRS
Distributed Resource Scheduler
It is a feature of a cluster
DRS continuously monitors utilization across the hosts and moves virtual machines to balance the computing capacity
DRS uses vMotion for its functioning
Types of DRS
Fully autom ated - The VMs are moved across the hosts automatically. No admin intervention required.
Partially automated - The VMs are moved across the hosts automatically during the time of VM bootup. But once up, vCenter
will provide DRS recommendations to admin and has to perform it manually.
Manual - Admin has to act according to the DRS recommendations
DRS prerequisites
Shared storage
Processor compatibility of hosts in the DRS cluster
vMotion prerequisites
vMotion is not working. What are the possible reasons?
Ensure vMotion is enabled on all ESX/ESXi hosts
Ensure that all vmware pre requisites are met
Verify if the ESXi/ESX host can be reconnected or if reconnecting the ESX/ESXi host resolves the issue
Verify that time is synchronized across environment
Verify that the required disk space is available
What happens if a host is taken to maintenance mode
Hosts are taken to maintenance mode during the course of maintenance
In a single ESX/ESXi setup, all the VMs need to be shutdown before getting into maintenance mode
In a vCenter setup If DRS is enabled, the VMs will be migrated to other hosts automatically.
How will you clone a VM in an ESXi without vCenter
Using vmkftools
Copy the vmdk file and attach to a new VM
Using VMware converter
Explain traverse folder
Allows or denies moving through a restricted folder to reach files and folders beneath the restricted folder in the folder
hierarchy.
Traverse folder takes effect only when the group or user is not granted the "Bypass traverse checking user" right in the Group
Policy snap-in. This permission does not automatically allow running program files.
1.
Maximum number of LUNs that can be attached to a host (ESXi 5.0)
o 256
2.
Maximum number of vCPUs that can be assigned to a VM (ESXi 5.0)
o 32
3.
What are the uses of ntdsutil tool?
o Some of the main uses of ntdsutil tool
i.
Authoritative Restore - Authoritatively restores the Active Directory database or AD LDS instance
ii.
ifm - Create installation media for writable and RODC setups (Offline DC provisioning)
iii.
metadata cleanup - Cleans up objects of decommissioned servers
iv.
roles - Transfers and seizes operations master roles
v.
set DSRM password - Resets DSRM administrator password
vi.
snapshot - Manages snapshots of the volumes that contain the Active Directory database and
log files
4.
FSMO roles and its failure scenarios
o http://www.systemadminguide.in/2013/07/fsmo-roles-in-nutshell.html
5.
IPv6 addresses and its DNS record
o 128 bit address
o Represented as 8 groups of 4 hexadecimel digits seperated by colons
o Represented by ‘AAAA’ record in DNS
o Uses DHCP v6 for addressing
6.
Loadbalancer vs Clustering
o Clustering
i.
Cluster is a group of resources that are trying to achieve a common objective, and are aware of
one another.
ii.
Clustering usually involves setting up the resources (servers usually) to exchange details on a
particular channel (port) and keep exchanging their states, so a resource’s state is replicated at
other places as well.
iii.
It usually also includes load balancing, wherein, the request is routed to one of the resources in
the cluster as per the load balancing policy
o Load Balancing
.
7.
Used to forward requests to either one server or other, but one server does not use the other server’s
resources. Also, one resource does not share its state with other resources.
Software installation using group policy
o This can be done using 2 methods
i.
Assigning
ii.
Publishing
o Assign :
.
If you assign the program to a user, it is installed when the user logs on to the computer. When
the user first runs the program, the installation is completed.
i.
If you assign the program to a computer, it is installed when the computer starts, and it is
available to all users who log on to the computer. When a user first runs the program, the
installation is completed.
o Publish :
.
You can publish a program distribution to users.
i.
When the user logs on to the computer, the published program is displayed in the Add or
Remove Programs dialog box, and it can be installed from there.
o msi packages are used for installation. Normal exe would not work.
o Windows cannot install the software while the user is already logged on. The user need to log off and log in
8.
Group policy security filtering for users. Which all users are in there by default. Members of Authenticated
Users group
o Security filtering is a way of refining which users and computers will receive and apply the settings in a
Group Policy object (GPO)
o In order for the GPO to apply to a given user or computer, that user or computer must have both Read and
Apply Group Policy (AGP) permissions on the GPO, either explicitly, or effectively through group
membership
o By default, all GPOs have Read and AGP both Allowed for the Authenticated Users group.
o The Authenticated Users group includes both users and computers. This is how all authenticated users
receive the settings of a new GPO when it is applied to an organizational unit, domain or site
9.
Relevance of host file and its location
o Came before the concept of DNS
o An FQDN is first checked in Host file
o Location : C:\Windows\System32\Drivers\etc
10.
L3 switch vs Routers
o L3 switches just have the ethernet ports only whereas the routers have WAN interfaces
o QoS is not available with L3 switches whereas in routers it can be enabled
o Routers have expansion slots and cards that allow them to use different media types, like serial
connections for T1 and T3 circuits
o Routers are more intelligent in handling packets
o L3 switches does not support NAT
11.
VLAN vs Subnet
o VLAN works at layer 2 while subnet is at layer 3
o Subnets are more concerned about IP addresses.
o VLANs bring more network efficiency
o Subnets have weaker security than VLANs as all the subnet uses the same physical network
12.
Contents of System state backup
o Registry
o COM+ Class Registration database
o Boot files, including the system files
o System files that are under Windows File Protection
o Active Directory directory service (If it is domain controller)
o SYSVOL directory (If it is domain controller)
o Cluster service inform ation (If it is a part of a cluster)
o IIS Metadirectory (If it is an IIS server)
o Certificate Services database (If it is a certificate server)
13.
Incremental vs Differential backups
o Incremental backup - Will take the backup of files whose archive bits are set and resets it after backup
o Differential backup - Will take the backup of files whose archive bits are set but does not reset it after
backup
14.
Robocopy
o Microsoft tool used for copying files effectively
o It has plenty of options to manage the copy process
15.
How do you patch microsoft applications? Frequency of patches released by Microsoft
o The Microsoft applications can be patched using WSUS
o In WSUS, we can create several computer groups to manage this patch process.
o MS patches are released once in a month
16.
Explain GPO, GPC & GPT
o GPO - Group Policy Object : Refers to the policy that is configured at the Active Directory level and is
inherited by the domain member computers. You can configure a GPO at the site level, domain level or OU
level. GPO stores policy settings in two locations GPC and GPT
o GPO behaviour : Local Policy > Site GPO > Domain GPO > OU GPO > Child OU GPO
o GPC - Group Policy Container :This is the AD portion of the group policy. This can be viewed using ADSI
edit. It stores version information, status information, and other policy information. When you create a new
GPO, an AD object of class groupPolicyContainer gets created under the System\Policies container within
your AD domain
o
o
17.
GPT - Group Policy Template : The GPT is where the GPO stores the actual settings. It stores software
policy script, and deployment information.
GPT is stored in SYSVOL share (\\DomainNameHere\SYSVOL\Policies) whereas GPC is stored in the AD
What is CPU affinity in VMware? Its impact on DRS?
o CPU refers to a logical processor on a hyperthreaded system and refers to a core on a non-hyperthreaded
system
o By setting CPU affinity for each VM, you can restrict the assignment of VMs to a subset of available
processors
o The main use of setting CPU affinity is when there are display intensive workloads which requires
additional threads with vCPUs.
o DRS will not work with CPU affinity
http://frankdenneman.nl/2011/01/11/beating-a-dead-horse-using-cpu-affinity/
18.
.
VMversion 4 vs VMversion 7
o Version 4
i.
Runs on ESX 3.x
ii.
Max supported RAM 64 GB
iii.
Max vCPUs 4
iv.
MS cluster is not supported
v.
4 NICs/VM
vi.
No USB Support
o Version 7
Runs on vSphere 4.x
i.
Max supported RAM 256 GB
ii.
Max vCPUs 8
iii.
MS cluster is supported
iv.
10 NICs/VM
v.
USB support
19.
What happens to the VMs if a standalone host is taken to maintenance mode?
o In case of standalone servers , VMware recommends that VMs should be powered off before putting the
server in maintenance mode
o If we put the standalone host in maintenance mode without powering off the VMs, it will remain in the
‘entering maintenance mode’ state until the VMs are all shutdown
o When all the VMs are powered down, the host status changes to ‘under maintenance’
http://pubs.vmware.com/vsphere-4-esxvcenter/index.jsp#using_drs_clusters_to_m anage_resources/c_using_maintenance_mode.html
20.
What is new in Windows server 2012
o Server core improvements: no need of fresh installation, you can add/remove GUI from server manager
o Remotely manage servers , add/rem ove roles etc using Server manager-manage 2008 and 2008 R2 with
WMF 3.0 installation, installed by default in Server 2012
o Remote server administration tools available for windows 8 to manage Windows server 2012 infrastructure
o Powershell v3
o Hyper-V 3.0
i.
supports upto 64 processors and 1 TB RAM per virtual machine
ii.
upto 320 logical hardware processors and 4 TB RAM per host
iii.
Shared nothing live migration, move around VMs without shared storage
o
o
ReFS(Resilient file system), upgraded version of NTFS- supports larger file and directory sizes. Removes
the 255 character limitation on long file names and paths, the limit on the path/filename size is now 32K
characters!
Improved CHKDSK utility that will fix disk corruptions in the background without disruption
21.
How does the backup software recognize that a file has changed since last backup?
o The files use a bit called archive bit for tracking any change in the file.
o The backup softwares normally checks the archive bit of the file to determine whether the file has to be
backed up or not
22.
How can you edit a vm template?
o The VM templates cannot be modified as such
o First , the VM template have to be converted to a virtual machine
o After making necessary machines in the virtual machine, convert the virtual machine back to template
23.
VMware configuration maximums
ESXi 5.5
ESXi 5.1
ESXi 5.0
ESXi 4.x
VMs
vCPU
64
64
32
8
RAM
1 TB
1 TB
1 TB
255 GB
vNIC
10
10
10
10
VMDK size
62 TB
1 TB
1 TB
2 TB for
8MB
block
Logical CPU
320
160
160
160
Mem ory
4 TB
2 TB
2 TB
1 TB
LUNs
256
256
256
256
LUN size
64 TB
64 TB
64 TB
64 TB
Virtual
Machines
512
512
512
320
Hosts
24. What is the major difference between Windows server 2008 and windows server 2012 in terms of AD
promotion?
In Win 2012, dcpromo has been depreciated. In order to make a Windows server 2012 to a domain controller, the ADDS
service has to be installed from the server manager. After installation, run the post-deployment configuration wizard from server
manager to promote the server as AD
25.
VMware hardware version comparison
What is vSAN?
It is a hypervisor-converged storage solution built by aggregating the local storage attached to the ESXi hosts managed by a
vCenter.
Recommended iSCSI configuration?
A separate vSwitch, and a separate network other than VMtraffic network for iSCSI traffic. Dedicated physical NICs should be
connected to vSwitch configured for iSCSI traffic.
What is iSCSI port binding ?
Port binding is used in iSCSI when multiple VMkernel ports for iSCSI reside in the same broadcast dom ain and IP subnet, to
allow multiple paths to an iSCSI array that broadcasts a single IP address.
iSCSI port binding considerations ?
Array Target iSCSI ports must reside in the sam e broadcast domain and IP subnet as the VMkernel port.
All VMkernel ports used for iSCSI connectivity must reside in the same broadcast domain and IP subnet.
All VMkernel ports used for iSCSI connectivity must reside in the same vSwitch.
Currently, port binding does not support network routing.
Recommended iSCSI configuration of a 6 NIC infrastructure ? (Answer changes as per the infrastructure requirements)
2 NICs for VM traffic
2 NICs for iSCSI traffic
1 NIC for vMotion
1 NIC for managem ent network
Post conversion steps in P2V
Adjust the virtual hardware settings as required
Remove non present device drivers
Remove all unnecessary devices such as serial ports, USB controllers, floppy drives etc..
Install VMware tools
Which esxtop metric will you use to confirm latency issue of storage ?
esxtop --> d --> DAVG
What are standby NICs
These adapters will only become Active if the defined Active adapters have failed.
Path selection policies in ESXi
Most Recently Used (MRU)
Fixed
Round Robin
Which networking features are recommended while using iSCSI traffic
iSCSI port binding
Jumbo Frames
Ports used by vCenter
80,443,902
What is 'No Access' role
Users assigned with the 'No Access' role for an object, cannot view or change the object in any way
When is a swap file created
When the guest OS is first installed in the VM
The active directory group, where the members will be ESXi administrators by default.
ESX Admins
Which is the command used in ESXi to manage and retrieve inform ation from virtual machines ?
vmware-cmd
Which is the command used in ESXi to view live performance data?
esxtop
Command line tool used in ESXi to manage virtual disk files?
vmkfstools
Port used for vMotion
8000
Log file location of VMware host
\var\log\vmware
Can you map a single physical NIC to multiple virtual switches ?
No
Can you map a single virtual switch to multiple physical NICs?
Yes. This method is called NIC teaming.
VMKernel portgroup can be used for:
vMotion
Fault Tolerance Logging
Management traffic
Major difference between ESXi 5.1 and ESXi 5.5 free versions
Till ESXi 5.1 free version there was a limit to the maximum physical memory to 32 GB. But from 5.5 onwards this limit has been
lifted.
What is IPAM server in Windows server 2012?
IPAM is IP Address Management server in Windows Server 2012. It enables central management of both DHCP and DNS
servers. It can also be used to discover, monitor, and audit DHCP and DNS servers.
How to promote a server to domain controller in Windows server 2012?
DCPROMO was the conventional tool used to promote a normal server to DC. This is now deprecated in Server 2012.
In Server 2012, you can convert a server into DC using the server manager console. Under Server Manager, add a new role
"Active Directory Domain Services"
How VMWare Kernel different from other kernels?
VMWare kernel is a proprietary kernel that means that it is a registered kernel by VMWare Company and it is not based
on any other kernel architecture or any other operating system. VMWare consists of a kernel that requires an
operating system to boot it. A service console is being provided when VMWare kernel is booted.
What are the features provided by VMWare for easy access?
VMWare provides several features to make it easy for the user to access and maintain it. The features are as follows:
• VMWare provides web browser interface
• It provides easy to use wizard to configure the settings
• It provides tools to easily create hosts and maintain it from one place
• It provides easy maintenance of Virtual machines
• It provides easy graphics to configure the VMWare settings for security
What are the features of VMWare Player?
VMWare player is a stand-alone player that comes with the installation of VMWare also. The features that make it more
popular are as follows:
• Creation of virtual machines can be done with easy install options. The creation and installation can be done directly
to the system.
• VMWare Player can run any virtual machine and it can be used by anyone, anywhere. It allows quick and easy
access, to take the advantage of security, portability and flexibility to manage the virtual machines.
• VMWare player allows sharing of virtual machines with other computers or users.
What are the different components used in VMWare infrastructure?
The different and major components used in VMWare infrastructure is as follows:
1. VMWare infrastructure consists of the lowest layer which acts as a ESX server host.
2. VMWare infrastructure also use the virtual centre server that keep tracks of all the VM related images and manage it
from one point.
3. VMWare infrastructure (VI) client: this allows the client to interact with user's applications that are running on
VMWare.
4. Web browser is used to access the virtual machines.
5. License server is used to create a server that provides licensing to the applications
6. Database servers are used to maintain a database.
5. What are the benefits of virtualization?
Virtualization is a creation of virtual machines and to manage them from one place. It allows the resources to be
shared with large number of network resources. Virtualization is having lots of benefits and they are as follows:
1. It helps in saving lots of cost and allows to easily maintaining it, in less cost.
2. It allows multiple operating systems on one virtualization platform.
3. It removes the dependency of heavy hardware to run the application.
4. It provides consolidating servers that are used for crashing of a server purpose
5. It reduces the amount of space being taken by data centres and company data.
6. What is the purpose of a Hypervisor?
Hypervisor is a program that manages the virtual machine. It also act like virtual machine manager that manages the
many virtual machines from one place. It allows multiple operating system to share single hardware host. Each
operating system in this consists of its own defined space consisting of space, memory and processor. It is used as a
controller program to control host processors and resources. It separates out the layer between many operating
systems so that one can't conflict with another one.
7. How ESX server related to VMWare?
ESX server is the enterprise edition of VMWare. It provides server virtualization platform that allows many operating
systems to be shared together in a convenient way and consists of a centralized management platform that is also
known as virtual centre. ESX server is a virtualization technique that is used to create cloud applications and allows
easy development of cloud platforms. It is related to VMWare as it is the upper layer of it.
8. What is the difference between ESX and GSX server?
GSX server acts as type 2 hypervisor that gets installed on the host operating system’s hardware like windows and
Linux. VMWare workstation gets mixed up with GSX server to provide it more functionality to run your applications
and operating systems. ESX server on the other hand, is type 1 hypervisor that runs its software directly on the
system’s hardware and it doesn’t require any operating system prior to its installation. It is level 0 hypervisor and it
has its own operating system.
9. What is the use of VMWare workstation?
VMWare workstation is software that allows user to run more than one operating system in there system. It provides virtualization to run
different applications on many operating systems at a single time. It saves the current configuration of operating system for the user in
the form of virtual machines. VMWare allows user to view there application and work with so many different OS without even switching
between the OSs.
10. What are the different types of extensions used by VMWare?
1. .log: is used to keep a log file to maintain a key for VMWare. This file allows user to see the problems encountered during any
installation or while using VMWare.
2. .nvram: is used to store the state of the virtual machine in system’s BIOS.
3. .vmdk: is a virtual disk file that is used to store the content of virtual machine.
4. .vmsd: stores the information and metadata of the system’s snapshots.
5. .vmsn: is used to store the snapshot state. It stores both the running state and the time when you have taken it.
6. .vmss: stores the suspended state of a virtual machine.
7. .vmtm: stores the configuration team data.
8. .vmx: store the primary configurations for the new virtual machine.
11. How virtual machine’s concept is different for host and guest systems?
Host system is the system that runs the operating system and over which the virtual platform can be installed. The virtual platform that
runs another operating system is called as guest operating system. Host and guest can be connected with each other by using the
virtual machines. A host system that runs all together its own operating system is called as virtualization host and the guest operating
system will be that, which get installed over that operating system.
12. What are some major differences between VMWare Server and ESX server?
• ESX server is a bare metter virtualation platform that is a physical server whereas, VMWare server needs an operating system to run
itself.
• ESX server is type 1 hypervisor virtualization platform whereas, VMWare server is a type-2 hypervisor virtualization platform.
• ESX server gives better performance then VMWare server, due to less overhead.
• ESX server have more features available then VMW are server.
• VMWare server is good to be used on small platforms and with less resources but, ESX server requires high specifications.
13. What is the use of Para-virtualization?
Para-virtualization is a virtualization technique that allows similar virtual machines to be created on particular hardware. It
allows many operating systems to run on host hardware at the sam e time. It makes good use of resources like processors,
memory and networking. It acts as a virtual machine monitor that has high performance and more efficient. It is used for
development, testing and production of the virtual machines. It also good in disaster recovery by moving the guest virtual
machine till the hardware is being repaired.
14. Why snapshots are really important in VMWare?
Snapshots are images that is been taken at a particular point from the virtual guest operating system. The snapshot consists of
the virtual machine configurations, memory and the devices that were present at the time of the snapshot. By doing this, you
can return back to virtual machine which might have become corrupted or might not be working. Snapshots can be taken
anytime according to your need and requirement. Snapshots can be saved and then system can be reverted back in case of
any disaster happened to your operating system.
15. What are the disadvantages associated with VMWare virtualization platform?
The disadvantage of VMW are virtualization platform is as follows:
• VMWare concept requires the knowledge of the concept.
• It requires money to buy the resources required for virtualization platform.
• It requires high end server with lots of high end configuration and specification that increases the cost.
• It requires different technologies that have to be implemented for the enterprise virtualization systems.
• Reliability decreases and cost increases in case of the system failures.
EXTRA ----
VMWARE L2 and L3 Interview Questions
VMWARE Questions
1). What's new with vsphere 5.1?
http://www.vmware.com/files/pdf/products/vsphere/vmware-what-is-new-vsphere5.pdf
2). Difference between ESX and ESXi?
3). How does vmotion works?
Live migration of a virtual machine from one physical server to another with VMware VMotion is enabled by three underlying
technologies.
First, the entire state of a virtual machine is encapsulated by a set of files stored on shared storage such as Fibre Channel or
iSCSI Storage Area Network (SAN) or Network Attached Storage (NAS). VMware vStorage VMFS allows multiple installations
of VMware ESX® to access the same virtual machine files concurrently.
Second, the active memory and precise execution state of the virtual machine is rapidly transferred over a high speed network,
allowing the virtual machine to instantaneously switch from running on the source ESX host to the destination ESX host.
VMotion keeps the transfer period imperceptible to users by keeping track of on-going memory transactions in a bitmap. Once
the entire memory and system state has been copied over to the target ESX host, VMotion suspends the source virtual
machine, copies the bitmap to the target ESX host, and resumes the virtual machine on the target ESX host. This entire
process takes less than two seconds on a Gigabit Ethernet network.
Third, the networks being used by the virtual machine are also virtualized by the underlying ESX host, ensuring that even after
the migration, the virtual machine network identity and network connections are preserved. VMotion manages the virtual MAC
address as part of the process. Once the destination machine is activated, VMotion pings the network router to ensure that it is
aware of the new physical location of the virtual MAC address.
Since the migration of a virtual machine with VMotion preserves the precise execution state, the network identity, and the active
network connections, the result is zero downtime and no disruption to users.
4). Pre-requisites of vMotion?
1.
ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same network segment
2.
ESX Servers must be managed by the sam e Virtual Center server
3.
ESX Must have compatible CPUs
4.
ESX Servers must have consistent Networks and Netwroks labels
5.
The VMs must be stored on shared storage - iSCSI or FC SAN or NAS/NFS
6.
The VMs cannot use local cd/floppy or internal only vrtual switches on the ESX server
5). Difference between h/w version 4 vs 7 vs 8 vs 9?
http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.upgrade.doc_50%2FGUID-68E5EDAE-66DE43F8-9420-F424AFEADB1D.html
6). What is storage DRS?
http://www.vmware.com/ap/products/datacenter-virtualization/vsphere/storage-drs.html
7). How is HA of vsphere 4.1 different from vsphere 5.x?
http://www.yellow-bricks.com/vmware-high-availability-deepdiv/
8). What is NMP (native multipathing)?
9). If one host is showing disconected to vcenter, how will you troubleshoot it?
10). What is PSOD, how will you troubleshoot it?
11). Where does the logs of hostd and vpx go?
12). what is in-memory filesystem and is introduced with which version?
13). Pr-requisites of FT?
14). What can be the maxium size of snapshot, how it grows?
15). Commands to create vswitch?
16). What is lockdown mode?
17). what is CPU ready time?
18). How to enable hot-add feature?
19). how to generate logs using CLI?
20). What is the default location for AAM logs?
21). Difference between VMF3 and VMFS5 filesystem?
22). How to troubleshoot VMs performance using CLI?
23). Difference between vpxa and hostd deamons?
24). How many simultaneous vmotions are possible in 1gigs n/w?
25). What are default roles in vcenter?
26). Whati s the difference between vmdk and flat.vmdk?
27). What is "shared nothing" vmotion and its pre-requisites?
28). Licensing model in 5.0 and how it is changed in 5.1?
29). How to upgrade from ESX 3.5 to 4.0 /4.x to 5.x?
30). What is a slot-size and how is it calculated?
31). Importance of VMware tools?
32). How many disk failures does RAID 5 support?
33). which is better RAID 10 or RAID 01
Storage Questions
1). What is zoning, different types of zoning?
2). Difference b/w soft and hard zoning?
3). Whati s LUN masking?
4). What is vault drive?
5). What is LUN masking and how is it different from zoning?
6. How many maximum number of disks can be placed in EMC clariion CX4 - 960
7). What is LCC and its importance?
8). What is difference between contcatination and Striping in lun expansion?
9). How is a LUN presented to a server, all steps like RAID grouping, LUN binding etc?
10). what is WW N and IQN
11). W hat are different types of backup techniques?
12). What is deduplication?
MORE – VMWARE
1. Is VMware Kernel a Linux/Unix Kernel?
VMware Kernel is a Proprietary Kernel and is not based on any of the UNIX operating systems, it's a kernel developed by
VMware Company.
2. Does the VMKernel boot by itself?
The VMKernel can't boot by itself, so it takes the help of the 3rd party operating system. In the case of VMware the kernel is
booted by RedHat Linux operating system which is known as service console.
3. The service console is developed based up on Redhat Linux Operating system; it is used to manage the VMKernel
4. Which command is used to restart webaccess service on vmware?service vmware-webaccess restart – this will restart
apache tomcat app
5. What is the command to restart ssh service on vmware?service sshd restart
6. What is the command to restart host agent(vmware-hostd) on VMware esx server?
service mgmt-vmware restart
7. What is the Path of the struts-config.xml?
/usr/lib/vmware/webAccess/tomcat/apache-tomcat-5.5.17/webapps/ui/WEB-INF/
8. What is the command to start the scripted install?
esx ks=nfs:111.222.333.444:/data/KS.config ksdevice=eth0
location 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 need access
All the ESX servers should be configured with Same number of Physical Nics (vSwitches) and Connectivity also should be
same, So that vMotion succeeds.
All the Virtual Machines are connected to one vSwitch with Different VLANS, this means the Physical Nic(vSwitch) needs to be
trunked with the sam e VLANS on the Physical Switch Port
10 What are the three port groups present in ESX server networking?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
11. What is the use of a Port Group?
The port group segregates the type of communication.
12. What are the types of communications which requires an IP address for sure?
Service Console and VMKernel (VMotion and iSCSI), these communications does not happen without an ip address (Whether it
is a single or dedicated)
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 the VMotion option for specific
vSwitch.
14. 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 the network. So this port
group enables communication between vSwitch and Physical 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 to happen, 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 host are connected to different VLANS, we need to install a separate physical nic (vSwitch) for every VLAN.
That is the reason vmware included the VLAN tagging for vSwitches. So every vSwitch supports upto 1016 ports, and BTW
they can support 1016 VLANS if needed, but an ESX server doesn’t support that many VM’s.
17. What is Promiscuous Mode on vSwitch? What happens if it sets to accept?If the promiscuous mode set to Accept, all
the communication is visible to all the virtual machines, in other words all the packets are sent to all the ports on vSwitch
If the promiscuous mode set to Reject, the packets are sent to inteded port, so that the intended virtual machine was able to
see the communication.
18. 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, you can see it in the
.vmx (VM Config) file. If it doesn't matches with the MAC address in the OS this setting does not allow incoming traffic to the
VM. So by setting Reject Option both MAC addresses will be remains same, and the incoming traffic will be allowed to the VM.
19. 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, you can see it in the .vmx (VM Config) file. If it doesn't matches with the
MAC address in the OS this setting does not allow outgoing traffic from the VM. So by setting Reject Option both MAC
addresses will be rem ains sam e and the outgoing traffic will be allowed from the VM.
20. What are the core services of VC?
VM provisioning, Task Scheduling and Event Logging
21. 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.
22. What is VC agent? What service it corresponds to? What are the minimum requisites for VC agent installation?VC
agent is an agent installed on ESX server which enables communication between VC and ESX server. The daemon associated
with it is called vmware-hostd, and the service which corresponds to it is called as mgmt-vmware, in the event of VC agent
failure just a restart of the service by typing the following command at the service console helps. " service mgmt-vmware restart
" VC agent is installed on the ESX server when we add it to the VC, so at the time of installation if you are getting an error like "
VC Agent service failed to install ", check the /Opt size whether it is sufficient or not.
23. How can you edit VI Client Settings and VC Server Settings?Click Edit Menu on VC and Select Client Settings to
change VI settings
Click Administration Menu on VC and Select VC Management Server Configuration to Change VC Settings.
24. What are the files that make a Virtual Machine?
.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
25. What are the devices that can be added while the virtual Machine running?
In VI 3.5 we can add Hard Disk and NIC's while the machine running. In vSphere 4.0 we can add Memory and Processor along
with HDD and NIC's while the machine running
26. How to set the time delay for BIOS screen for a Virtual Machine?
Right Click on VM, select edit settings, choose options tab and select boot option, set the delay how much you want.
27. What is a template?
We can convert a VM into Template, and it cannot be powered on once it’s changed to template. This is used to quick
provisioning of VM's.
23. What to do to customize the windows virtual machine clone?
Copy the sysprep files to Virtual center directory on the server, so that the wizard will take the advantage of it.
24. What to do to customize the linux/unix virtual machine clone?
VC itself includes the customization tools, as these operating systems are available as open source.
25. Does cloning from template happen between two datacenters?
Yes... it can, if the template is in one datacenter, we can deploy the vm from that template in another datacenter without any
problem.
26. 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, then the snapshot failed. If it is mapped as virtual then we can take a snapshot of
it.
If you configure the VM with Mapped LUN's as physical, you need to remove it to take a snapshot.
27. 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).
28. What are the requirements for Converting a Physical machine to VM?
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plug-in
A server to import/export virtual machines
29. What is VMWare consolidated backup?
It is a backup framework, which supports 3rd party utilities to take backups of ESX servers and Virtual Machines. It’s not a
backup service.
30. To open the guided consolidation tool, what are the user requirements?
The user must be member of administrator, the user should have "Logon as service" privileges - To give a user these
privileges, open local sec policy, select Logon as service policy and add the user the user should have read access to AD to
send queries
31. Difference between HA and Vmotion?
VMotion and HA are not related and are not dependents of each other. DRS has a dependency on vMotion,but not HA. HA is
used in the event that a hosts fails you can have your virtual machines restart on another host in the cluster. vMotion allows you
to move a virtual machine from one host to another while it is running without service interruption. Ideally you will utilize
vMotion, HA and DRS within your cluster to achieve a well balanced VI environment.
So HA fail over is not really seamless since you mentioned it has virtual machines restart on another host in the
Cluster? No, your VM's will go down If there is a host failure and then HA will restart them on another ESX Host in the cluster.
This is where DRS will take over and start to balance out the load across the remaining ESX Hosts in the cluster using vmotion.
32. What is DRS? DRS : Distributed Resource Scheduling (Youtube Video)
VMware DRS dynamically balances computing capacity across a collection of hardware resources aggregated into logical
resource pools, continuously monitoring utilization across resource pools and intelligently allocating available resources among
the virtual machines based on pre-defined rules that reflect business needs and changing priorities. When a virtual machine
experiences an increased load, VMware DRS automatically allocates additional resources by redistributing virtual machines
among the physical servers in the resource pool. VMware DRS allows IT organizations to:
• Prioritize resources to the highest value applications in order to align resources with business goals
• Optimize hardware utilization automatically and continuously to respond to changing conditions
• Provide dedicated resources to business units while still profiting from higher hardware utilization through
resource pooling.
• Conduct zero-downtime server maintenance
* Lower power consumption costs by up to 20 percent.
33. What is HA? HA : High Availability (Youtube video)
vSphere High Availability (HA) delivers the availability needed by many applications running in virtual machines, independent of
the operating system and application running in it. HA provides uniform, cost-effective failover protection against hardware and
operating system failures within your virtualized IT environment.
·
·
Monitors virtual machines to detect operating system and hardware failures.
Restarts virtual machines on other physical servers in the resource pool without manual intervention when server
failure is detected.
·
Protects applications from operating system failures by automatically restarting virtual machines when an operating
system failure is detected.
34. What is DPM in VMWARE? DPM : Distributed Power Management
VMware Distributed Power Management (DPM) is a pioneering new feature of VMware DRS that continuously monitors
resource requirements in a VMware DRS cluster. When resource requirements of the cluster decrease during periods of low
usage, VMware DPM consolidates workloads to reduce power consumption by the cluster. When resource requirem ents of
workloads increase during periods of higher usage, VMware DPM brings powered-down hosts back online to ensure service
levels are met. VMware DPM allows IT organizations to:
• Cut power and cooling costs in the datacenter
• Automate management of energy efficiency in the datacenter
What is dvSwitch? Distributed vSwitch
It’s a new feature introduced in vSphere4.0.The configuration of vDS is centralized to vCenter. The ESX/ESXi 4.xand ESXi 5.x
hosts that belong to a dvSwitch do not need further configuration to be compliant. Distributed Switches provide similar
functionalities to vSwitches. dvPortgroups is a set of dvPorts. The vDS equivalent of portgroups is a set of ports in a vSwitch.
Configuration is inherited from dvSwitch to dvPortgroup, like what happens for vSwitch/Portgroup. Virtual machines, Service
Console interface (vswif), and VMKernel interfaces can be connected to dvPortgroups just as like they could be connected to
portgroups in vSwitches Administrative rights are required to create the following virtual adapters on each ESX/ESXi host
dvSwitch in vCenter:
·
·
Service Console and VMKernel interfaces
Physical NICs and their assignment to dvSwitch Uplink groups
Configuring vNetwork Distributed Switch using vCenter
What is FT in vmware? FT : Fault Tolerance for Virtual Machines
vSphere Fault Tolerance (FT) provides continuous availability for applications in the event of server failures, by creating a live
shadow instance of a virtual machine that is in virtual lockstep with the primary instance. By allowing instantaneous failover
between the two instances in the event of hardware failure, FT eliminates even the smallest chance of data loss or disruption.
VMware Fault Tolerance FAQ
What is vApps in vmware?
vApps : vApp is a container same as resource pool, but it is having some features of virtual machines, a vApp can be powered
on or powered off, and it can be cloned too.
More details on vApps along with a video.
What is vSafe?
vmSafe : VMsafe's application programming interfaces are designed to help third-party vendors create virtualization security
products that better secure VMware ESX, vShield Zones is a security tool targets the VMware administrator.
In other words VMware VMsafe™ is a program for integrating partner security solutions into VMware-virtualized environments,
offering visibility, control and choice to customers. The result is an approach to virtualized security that provides custom ers with
a choice of enhanced security and IT compliance solutions enabling comprehensive protection for virtual datacenters and cloud
environments
What is vShields?
vShield : VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual network traffic. This threepart series describes vShield Zones, explains how to install it and provides useful management tips.
ALL ABOUT DNS _ DOMAIN NAME SYSTEM
1) What is DNS?
Ans: Its a distributed naming system which is organized in a hierarchy. Its used in private network or internet by computers,
services or entities lying within.
2) What is Domain Naming Service?
Ans: A domain naming service translates names to IP address and vice-verse. Since humans can't remember numbers but
names, this system was designed so that it helps them recognize a service or computer by nam e but computers are able to talk
to each other using IP addresses.
3) What is forward look up?
Ans: When DNS server is queried for a name and it returns an IP address in reply, its called forward lookup. For example
when I type yahoo.com in the internet explorer, the dns server returns an IP address to which a computer is able to connect.
4) What is reverse lookup?
Ans: When a DNS client queries a DNS server about an IP and the DNS server responds by providing a name is known as
reverse lookup in DNS.
5) What is DNS cache?
Ans: All the queries that a DNS client does, its results are saved by it in its temporary storage so that next time when it has to
find out about an IP or name, it would first look into the cache. If its not there, then only it'll contact the DNS server. This
temporary storage is called DNS cache. It helps increase the speed of name resolution for frequently queried names.
Q: How DNS query works?
Ans: The answer is a detailed one. Please visit this page to know more.
6) What are DNS forwarders?
Ans: When we setup DNS servers we want queries for internet names to be forwarded to ISP DNS so that those can be
resolved by the server to which they have been forwarded and returned back to my DNS server. These servers to which the
DNS queries are forwarded to are called "DNS Forwarders".
Internet names are just one example, we could as well set up forwarders for a particular domain name as well.
7) What is Primary DNS Server?
Ans: Its the Writable copy of the DNS where the DNS database is stored. All the changes related to creation, deletion or
modification of a DNS record or Zone is done on this server.
8) What is secondary DNS?
Ans: Secondary DNS servers are read only replica of primary DNS servers. They are created to distribute the load of primary
DNS servers and to prevent the writable copy of the DNS to the external world. Secondary DNS servers do the same job of
carrying out name resolution by using a read only copy of the primary DNS server database. They get this copy of primary DNS
server database using one of the DNS Zone transfer methods. They are AXFR, IXFR and Full Zone Transfer.
IXFR - Incremental Zone Transfer.
AXFR - augmented Zone transfer.
Full/Complete Zone Transfer
To know more about Zone transfer in detail please visit this page and read thoroughly.
9) What is Active Directory Integrated DNS?
Ans: Active Directory–integrated DNS enables Active Directory storage and replication of DNS zone databases. Windows 2000
DNS server, the DNS server that is included with Windows 2000 Server, accommodates storing zone data in Active Directory.
When you configure a computer as a DNS server, zones are usually stored as text files on name servers — that is, all of the
zones required by DNS are stored in a text file on the server computer. These text files must be synchronized among DNS
name servers by using a system that requires a separate replication topology and schedule called a zone transfer However, if
you use Active Directory–integrated DNS when you configure a domain controller as a DNS name server, zone data is stored
as an Active Directory object and is replicated as part of domain replication.
10) What is stand alone DNS Server?
Ans: A non AD integrated DNS can be termed as standalone DNS server. Its the only DNS server in an environm ent.
11) How DNS can do load balancing?
Ans: DNS can do load balancing by using the following methods:
1) DNS Round Robin
2) Using weights on DNS records. For example we can define weight on each MX record to define how much of load we
want a particular server to handle.
12) What is Secondary Zone?
Ans: The zone hosting the read only copy of a Primary DNS server's writable copy of Zone is called a secondary zone.
13) What is SRV record?
Ans: The SRV RR identifies the host(s) that will support particular services. The MX RR is a specialised example of service
discovery while the SRV RR is a general purpose RR to discover any service.
14) What is A record and PTR record?
Ans: "A" records are host records where a name is mapped to the IP address assigned to it. A "PTR" records where IP
addresses are mapped to a name.
15) What is a Stub Zone?
Ans: A stub zone is a copy of a zone that contains only those resource records necessary to identify the authoritative Domain
Name System (DNS) servers for that zone. A stub zone is used to resolve names between separate DNS nam espaces. This
type of resolution may be necessary when a corporate merger requires that the DNS servers for two separate DNS
namespaces resolve names for clients in both namespaces.
A stub zone consists of:
The start of authority (SOA) resource record, name server (NS) resource records, and the glue A resource records for the
delegated zone.
16) What is a delegated DNS zone? When do we use it?
Ans: Delegated DNS zones are created when we want the name resolution of subdomains or child domains to be broken up
with in DNS. For more details please visit this page.
17) Steps by Step method to install DNS in Windows?
Ans: Step by step method to install DNS in windows 2003 is given here.
Step by Step method to install DNS in Windows 2008 is given here.
19) How to troubleshoot Active Directory related DNS problems using DCDiag tool?
Ans: Please find the steps here. Do look for part 2 of this youtube video.
20) New features of DNS in Windows 2008?
·
Background zone loading: DNS servers that host large DNS zones that are stored in Active Directory Domain
Services (AD DS) are able to respond to client queries more quickly when they restart because zone data is now loaded in the
background.
·
IP version 6 (IPv6) support: The DNS Server service now fully supports the longer addresses of the IPv6
specification.
·
Support for read-only domain controllers (RODCs): The DNS Server role in Windows Server 2008 provides primary
read-only zones on RODCs.
·
Global single names: The GlobalNames zone provides single-label nam e resolution for large enterprise networks that
do not deploy Windows Internet Name Service (WINS). The GlobalNam es zone is useful when using DNS name suffixes to
provide single-label name resolution is not practical.
·
Global query block list: Clients of such protocols as the Web Proxy Auto-Discovery Protocol (WPAD) and the Intrasite Automatic Tunnel Addressing Protocol (ISATAP) that rely on DNS name resolution to resolve well-known host names are
vulnerable to malicious users who use dynamic update to register host computers that pose as legitimate servers. The DNS
Server role in Windows Server 2008 provides a global query block list that can help reduce this vulnerability.
Watch the videos and have fun learning answers to the above mentioned questions and gain much more additional knowledge
as well. Hope it helps you all.
Download DNS Videos
+ Download one by one if you don't have a live ID or a hotmail ID.
What is EDNS?
Its called "Extended mechanisms for DNS". More details can be found at the links given below:
http://spanougakis.wordpress.com/2011/05/01/edns-what-is-all-about-2/
http://social.technet.microsoft.com/Forums/en-US/winservergen/thread/b4e22807-a4ed-4a9e-be23-cdcc2b77ed22/
http://sysadminthings.blogspot.ca/2011/09/things-i-never-knew-about-dns-edns.html
Q: When does DNS works using UDP and when it uses TCP?
Ans: DNS uses both TCP and UDP for valid reasons. Note that UDP messages are not larger than 512 Bytes and are
trucncted when greater than this size. So DNS uses TCP for Zone transfer and UDP for name queries either regular (primary)
or reverse. UDP can be used to exchange small information whereas TCP must be used to exchange information larger than
512 bytes. If a client doesn't get response from DNS it must retransmit the data using TCP after 3-5 seconds of interval.
The Network Files, Case #53: Diagnosing Diseases of DNS
Network troubleshooters soon learn that the first place to look when the network stops working is DNS... and soon after that,
they learn that the in-the-box DNS troubleshooting tool, nslookup, is a pretty basic answer. So if keeping DNS working is part of
your job, don't miss this "beyond the basics" DNS troubleshooting session presented by Mark Minasi, the author of the
Mastering Windows Server books that have taught DNS to more Windows admins than any other. We start with "dig," the
nslookup replacement that is a must-know for DNS techies. Then we see how to give your troubled DNS queries a thorough
workup with Network Monitor (even if you've never used Netmon), where you'll be able to find out why those dynamic updates
aren't happening. From there, get the scoop on "EDNS," a feature of DNS servers since 2003 that has been blamed -- wrongly
-- for a host of DNS ills. After that, see how to take your DNS system's pulse with DNSLint, a free, not-to-be-missed utility. Then
see how to understand what those DNS logs are REALLY saying. Attend this talk and you'll soon be known as "Doctor DNS!"
Difference between vSphere, ESXi and vCenter
VMware Inc. is a software company that develops many suite of software products specially for providing
various virtualization solutions. There are many cloud products, datacenter products, desktop products and
so on.
vSphere is a software suite that comes under data center product. vSphere is like Microsoft Office suite which
has many software like MS Office, MS Excel, MS Access and so on. Like Microsoft Office, vSphere is also a
software suite that has many software components like vCenter, ESXi, vSphere client and so on. So, the
combination of all these software components is vSphere. vSphere is not a particular software that you can install
and use, “it is just a package name which has other sub components”.
ESXi, vSphere client and vCenter are components of vSphere. ESXi server is the most important part of
vSphere. ESXi is the virtualization server. It is type 1 hypervisor. All the virtual machines or Guest OS are
installed on ESXi server. To install, manage and access those virtual servers which sit above of ESXi server, you
will need other part of vSphere suit called vSphere client or vCenter. Now, vSphere client allows administrators to
connect to ESXi servers and access or manage virtual machines. vSphere client is installed on the client machine
(e.g. Administrator’s laptop). The vSphere client is used from client machine to connect to ESXi server and do
management tasks. So now what is vCenter? Why we need it? Try cloning existing virtual machine using just
a vSphere client without vCenter server.
vCenter server is similar to vSphere client but it’s a server with more power. vCenter server is installed on
Windows Server or Linux Server. VMware vCenter server is a centralized management application that lets you
manage virtual machines and ESXi hosts centrally. vSphere client is used to access vCenter Server and
ultimately manage ESXi servers. vCenter server is compulsory for enterprises to have enterprise features like
vMotion, VMware High Availability, VMware Update Manager and VMware Distributed Resource Scheduler
(DRS). For example, you can easily clone existing virtual machine in vCenter server. So vCenter is another
important part of vSphere package. You have to buy vCenter license separately.
The diagram above shows vSphere suite in a more descriptive way. vSphere is a product suite, ESXi is a
hypervisor installed on a physical machine. vSphere Client is installed on laptop or desktop PC and is used to
access ESXi Server to install and manage virtual machines on ESXi server. vCenter server is installed as virtual
machine on top of ESXi server. vCenter server is a vSphere component which is mostly used in large
environment where there are many ESXi server and dozens of virtual machines. The vCenter server is also
accessed by vSphere client for management purpose. So, vSphere client is used to access ESXi server directly
in small environment. In larger environment, vSphere client is used again to access vCenter server which
ultimately manages ESXi server.
In How to Import a Virtual Machine into ESXi Part 1: P2V Migration, I described cold
and hot migrations, the difference between physical-to-virtual (P2V) and virtual-tovirtual (V2V) migrations, and how to perform a P2V migration using VMware vCenter
Converter. In the second half of this two-part series, I’ll explain how to import an
existing virtual machine (VM) into an ESX/ESXi Server.
VMware vCenter Converter supports several different kinds of virtual machines. It
can import into ESX/ESXi virtual machines created in a VMware application or in a
competing product. It’s important to note, however, that not all virtualization products
use the same virtualization method when running guest machines. VMware
Workstation, VMware Player, VMware Server, VMware Fusion, Parallels Desktop,
Microsoft Virtual PC and Microsoft Virtual Server — all of which are compatible with
vCenter Converter — use hosted virtualization.VMware ESX/ESXi Server and
Microsoft Hyper-V Server, on the other hand, use bare-metal virtualization to run
VMs. The former group of software runs on top of an existing operating system,
while the latter group runs on top of the host hardware.
These differences mean little once vCenter Converter has completed the conversion
process, but virtual machines created in hosted virtualization software require
different migration steps from virtual machines created in bare-metal virtualization
platforms.
Just about all V2V migrations are cold migrations, which require that the source
system be powered off during the conversion process. It is, however, possible to
perform a hot migration of a virtual machine using the hot migration method as
described in How to Import a Virtual Machine into ESXi: Part 1. After installing
vCenter Converter Standalone to the virtual machine, launch the Conversion wizard.
Select “Powered-On Machine” from the drop-down menu, click “Local Machine,” and
then follow the same steps as described in the section P2V: Hot Migration.
One thing to keep in mind before performing a hot migration, however, is that, in
some instances, vCenter Server can interfere with the migration process. If the
source system is inside a Distributed Resource Schedule (DRS) cluster that vCenter
Server controls, DRS Power Management (DPM) will turn off the ESX/ESXi host that
vCenter Converter is working with. Change DPM to Manual via the cluster’s Settings
screen before performing the hot migration. Once the migration is complete, revert
Power Management to its previous configuration.
Although hot migrations have their purpose, they’re only needed when a virtual
machine is too important to be taken offline. In all other instances, you should
perform a cold migration. The following steps detail the offline conversion process.
V2V: Cold Migration
1. Power down the source machine before proceeding. Select “Convert Machine”
from the toolbar to launch the Conversion wizard.
See steps 2a and 2b to import a VM from a hosted virtualization platform; See
steps 3a and 3b to import a VM from a bare-metal virtualization platform.
2a. Hosted Virtualization: Choose “VMware Workstation or Other VMware Virtual
Machine” or “Backup Image or Third-Party Virtual Machine” from the Source Type
drop-down menu, depending on which platform the source machine is using.
2b. Hosted Virtualization: Enter the full file or network path linking to the virtual
machine. Supported third-party platforms include Microsoft Virtual PC and Microsoft
Virtual Server (.vmc), and Parallels Desktop (.pvs). Use .vmx for virtual machines
created in VMware. Note that if you’re importing a VM from Microsoft Virtual PC, you
should remove the Virtual PC Additions from the machine, as they can interfere with
the conversion process.
Enter the login credentials for the server if accessing a network share, and then click
“Next.” Skip to step 4.
3a. Bare-Metal Virtualization: Select “VMware Infrastructure Virtual Machine” or
“Hyper-V Server” from the drop-down menu on the Source System screen. If vCenter
Converter is not installed to Hyper-V Server, a prompt will appear requesting
permission to install the application to the system. Confirm the installation of the
software to proceed with the conversion.
Enter the server address and login credentials for the ESX/ESXi or Hyper-V Server.
Click “Next” to go to the Source Machine screen.
3b. Bare-Metal Virtualization: Search through the inventory to locate the source
system. If you’re accessing ESX/ESXi through vCenter Server, choose “Hosts and
Clusters” or “VMs and Templates,” depending on where the source machine is
housed. Select the virtual machine to import into the ESX/ESXi Server, and then
click “Next.”
4. Select “VMware Infrastructure Virtual Machine” from the Select Destination Type
drop-down menu. Enter the address, user name, and password for ESX/ESXi Server
into the required fields. Click “Next” to go to the Destination Virtual Machine screen.
5. Enter a new name for the destination machine or use the default name. Select a
destination location for the VM if managing ESX/ESXi through vCenter Server. Click
“Next” to go to the Destination Location screen.
6. Select a host, resource pool, or cluster to accommodate the virtual machine;
select a datastore where the files associated with the virtual machine should be
stored (optional); and then select the virtual hardware version from the drop-down
menu (optional). Use Version 4 for machines running ESX/ESXi 3.x, Version 7 for
machines running ESX/ESXi 4.x, and Version 8 for machines running ESX/ESXi 5.x.
Click “Next” to go to the Options screen.
7. Click “Edit” to make changes to a hardware device. If you’re importing a virtual
machine based on the Microsoft Windows operating system, select “Advanced” from
the middle pane to view the Post-Conversion tab. Uncheck “Remove System
Restore Checkpoints on Destination.” Check “Reconfigure Destination Virtual
Machine” to personalize the OS (e.g., create a unique name and password, enter a
new product license, or change the workgroup or domain settings). Click “Next” after
making the desired changes.
8. Review your selections on the Summary screen; then click “Finish” to begin
importing the VM.