Wednesday, 6 December 2017

NFS Versions & Packages Required for NFS (LINUX/UNIX)

NFS: Network File System (NFS) protocol allow Linux client to mount remote file systems and interact with those file systems as they are mounted locally.
  • NFS was developed by Sun Microsystems in 1980
  • NFS stand for Network File System
  • NFS is used to share files and printer between Linux / Unix systems
  • Red Hat Enterprise Linux 6 supports NFSv2, NFSv3, and NFSv4 clients.
  • By default RHEL6 use NFSv4 if the server supports it.
Packages required for NFS:
  • nfs-utils - The nfs-utils package provides a daemon for the kernel NFS server and related tools, which provides a much higher level of performance than the traditional Linux NFS server used by most users.
  • portmap - The portmap package should be installed on any machine which acts as a server for protocols using RPC.
  • nfs4-acl-tools - This package contains command line and GUI & ACL utilities for the Linux NFSv4 client.

NFS Versions:
NFSv1:
1> NFSv1 was the development stage of NFS protocol.
2> It was used only for in house experimental purpose. 

NFSv2:

1> NFSv2 supports only 32 bit.
2> NFSv2 only allowed the first 2 GB of a file to be read
3> NFSv2 operated only over UDP

NFSv3:

1> NFSv3 supports 64 bit file system.
2> NFSv3 can handle files larger than 2 GB.
3> NFSv3 supports asynchronous writes on the server. asynchronous writes improve write performance.
4> NFSv3 supports additional file attributes in many replies, to avoid the need to re-fetch them.
5> NFSv3 supports READDIRPLUS operation. READDIRPLUS operation get file handles and attributes along with file names when scanning a directory.
6> NFSv3 supports TCP. Using TCP as a transport made NFS over a WAN more feasible.


NFSv4:

1> NFSv4 retains all NFSv3 advantages.
2> NFSv4 supports ACLs.
3> NFSv4 uses the virtual file system to present the server's export.
4> NFSv4 supports Pseudo file system. Pseudo File System provide maximum flexibility. 
5> Exports Pathname on servers can be changed transparently to clients.
6> NFSv4 have locking operations as the part of protocol which keep track of open files and delegations.
7> NFSv4 works through firewalls and on the Internet.

DHCP Configuration path in LINUX

/usr/share/doc/dhcp*/dhcpd.conf.sample

Monday, 4 December 2017

IPv6

IPV6: (Important Questions)



Q Types of IPv6 Unicast Addresses:
1> Global Unicast Addresses
2> Site local Addresses
3> Link Local Addresses

Q What is IPv6 Equivalent to IPv4 Address 0.0.0.0 ?
Answer: ::

Q What is IPv6 Equivalent to loopback IP 127.0.0.1?
Answer: ::1

Q What is IPv6 Equivalent to loopback IP 127.0.0.1/8?
Answer: ::1/128

Q What is IPv6 Equivalent to IPv4 Multicast Address 224.0.0.0/4
Answer: FF00::/8

Q What is the IPv6 Equivalent to IPv4 Autoconfigured 169.254.0.0/16
Answer: FE80::/64

Q What is the IPv6 Equivalent to IPv4 Private Address
Answer: ULA (Unique Local Addresses, or Unique Local IPv6 Unicast Addresses to give them their full name) are IPv6's equivalent of IPv4's “private” addresses

Q How many bytes does an IPv6 address contain ?
Answer: The IPv6 address is 128 bits (16 bytes).

Q How many bytes does an IPv4 addresss contain ?
Answer: The IPv4 address is made up of 32 bits (4 bytes)

Q What is the IPv6 is equivalent of Subnet Mask in IPv4 ?
Answer: The prefix-length in IPv6 is the equivalent of the subnet mask in IPv4.

Q What is the description of IPV6 Prefixes 2000::/3
Answer: Global Unicast Address

Q What is the description of IPV6 Prefixes FE80::/8
Answer: Link Local Unicast Address

Q What is the description of IPV6 Prefixes FC00::/7
Answer: Unique Local Unicast Address

Q Which type of Ipv6 Address do you need if you wish to connect to IPv6 Internet from Server ?
1> Global Address
2> Link Local Address
3> Umique Local Address
4> Site-Local Address
Answer: Global Address

Windows Interviews questions

Q During a Windows Server 2012 installation, the Setup program copies the files for all of the operating system components from the installation medium into a directory. What is that directory named?
A WinSxS

Q What role of Windows Server 2012 enables administrators to manage image files that remote workstations can use to start up and install Windows over the network?
A Windows Deployment Services

Q What command line utility can you use to join a computer to a domain when the computer does not have a working network connection to any of the domain controllers for that domain?
A djoin

Q What are the first three bytes of every MAC address range usable in the Virtual Switch Manager?
A 00-15-5D

Q Does Windows Server 2012 allow Remote Desktop connections by default?
A No

Q On network does Automatic Private IP Addressing (APIPA) assign IPv4 addresses?
A 169.254.0.0/16

Q Which feature of Windows Server 2012 enables administrators to combine the bandwidth of multiple network interface adapters, providing increased performance and fault tolerance?
A NIC Teaming

Q What type of DNS record is used to store IP address to name mappings used for reverse lookups?
A PTR

Q Which Windows service do you need to start manually from the Services console before you can use AppLocker?
A Application Identity

Q What feature of Windows Server 2012 enables a server to concatenate storage space from individual physical disks and allocate that space to create virtual disks of any size supported by the hardware?
A Storage Spaces

Q What Windows utility enables clients running Windows XP and Windows Server 2003 to accept policy-based printer deployments?
A PushPrinterConnections.exe

Q How many virtual network adapters can you create on a Windows Server 2012 Hyper-V server?
A Eight synthetic adapters and four emulated adapters

Q Which print sharing option minimizes resource utilization on the print server by forcing the print clients to perform the bulk of the print processing?
A Render Print Jobs On Client Computers

Q How many logical processors are supported by Microsoft Windows Server 2012?
A 640

Q What command-line utility is required to create the domain controller installation media that includes a copy of the AD DS database so that you can use the Install From Media (IFM) option in the Active Directory Domain Services Configuration Wizard?
A ntdsutil.exe

Q How many Volume Shadow Copies does Windows Server 2012 support?
A 64

Q Which editions of Microsoft Windows Server 2012 include the Hyper-V role ?
A Microsoft Windows Server 2012 Datacenter
Microsoft Windows Server 2012 Standard

Q What are the four editions of Windows Server 2012?
A Windows Server 2012 Datacenter
  • Windows Server 2012 Essentials
  • Windows Server 2012 Foundation
  • Windows Server 2012 Standard

Q What is not one of the Storage Layout options supported by Windows Server 2012?
A RAID-5
Q What feature gives Windows Server 2012 the ability to retrieve source files for a feature from another location, such as from an image file ?
A Features on Demand

Q How many physical disks are required to support the Parity storage layout?
A 3

Q What is the correct term for a DNS client?
A Resolver

POWER SHELL INTERVIEW Questions :

Q Utility To Configure (Core) Server parameter using powershell ?
A sconfig

Q What PowerShell command would you use to get a list of roles and features installed on a computer running Windows Server 2012?
A Get-WindowsFeature

Q What PowerShell command would you use to install the Hyper-V role on a computer running Microsoft Windows Server 2012?
A Install-WindowsFeature -Name Hyper-V -ComputerName <name> -IncludeManagementTools -Restart
Q Which two PowerShell commands could you use to install a role or feature on a computer running Windows Server 2012?
A Add-WindowsFeature
Install-WindowsFeature

Q PowerShell Command to install DHCP roles ?
A Install-WindowsFeature -Name DHCP -Restart

QPowershell Command to install or ADD DNS roles ?
A Add-WindowsFeature -Name DNS -Restart

QPowershell Command to install FailOver-Clustering ?
A Install-WindowsFeature Failover-Clustering

Q Powershell command to install FailOver-clustering including Management Tools?
Ainstall-WindowsFeature -Name Failover-Clustering -IncludeManagementTools

Q What PowerShell command would you use to join a computer to a domain?
A netdom join %ComputerName% /domain:/userd:/passwordd:*

Q What PowerShell command would you use to promote a computer running Windows Server 2012 to an Active Directory Domain Controller and make that new Domain Controller responsible for a new forest?
A Install-AddsForest -DomainName “example.com

Q What PowerShell command would you use to demote a domain controller?
A Uninstall-ADDSDomainController –ForceRemoval –LocalAdministratorPassword <password> –Force

Q What PowerShell command would you use to convert a Windows Server 2012 Server Core installation to the full GUI option?
A Install-WindowsFeature Server-Gui-Mgmt-Infra,Server-Gui-Shell -Restart

Q what powershell command to restart a computer ?
A restart-computer

Q Explain with an example how you can map a network drive in PowerShell?
A # PowerShell Map Network Drive
$Net = $( New – Object – ComObject Wscript.Network )
$Net.MapNetworkDrive( “S:”, \\expert\guru99 )

Q Explain how you can find in PowerShell that all the sql services are on one server?
A There are two ways to do this
  • get-wmiobject win32_service l where-object {$_name-like “*sql*”}
  • get-service sql*
Q What is the code to find the name of the installed application on the current computer?
A Get-WmiObject-Class Win32_Product- ComputerName . | Format-wide-column1

Q Explain how you can rename a variable?
A To rename a variable,
Rename-Item- Path Env: MyVariable –NewName MyRenamedVar

Q Explain how you can convert the object into HTML?
A To convert the object into HTML
Get-Process l Sort-object – property CPU –descending l convert to – HTML l Out-file “process.html”

Q How many shared printers are shared on a print server ?
A $(Get-WmiObject win32_printer -ComputerName "Your Print Server Name" |? {$_.Shared -eq $True}).count

Q Powershell command to get Print Queue Count ?
A$(Get-WmiObject win32_printer -ComputerName "Your Print Server Name" |? {$_.Shared -eq $True}).count

Q To Install FailOver Clustering Feature Using Power Shell ?
A Install-WindowsFeature -Name Failover-Clustering -IncludeManagementTools

Q To Import FailOver Clustering Modules ?
A Import-Module FailoverClusters

Q To Confirm Failover Clustering Modules imported Successfully ?
A Get-Module -ListAvailable

LDAP & Active Directory:

Q What are all the Active Directory Partitions?
Schema
Configuration
Domain
Application partition

Q What is NETLOGON folder?
Netlogon folder contain logon/logoff/startup/shutdown scripts which is inside the Sysvol folder

Q What is junction point ?
Answer: Junction point:
1> It is a physical location on a hard disk that points to data that is located elsewhere on the hard disk or on another storage device.
2> Junction points look like folders and behave like folders but they are not folders.
3> A junction point contains a link to another folder.
4> When a program opens it, the junction point automatically redirects the program to the folder to which the junction point is linked

Q Command to force Sysvol Replication on 2008 & 2012 using Dfsrdiag SyncNow command
Answer: Dfsrdiag syncnow /rgname:”domain system volume” /partner:dc2 /time:1 /verbose

Q Command to force Replication of others folders on 2008 & 2012 using Dfsrdiag SyncNow command
Answer: Dfsrdiag SyncNow /partner:dfsserver2 /rgname:domainname\app\folder1 /member:dfsserver1 /time:5

Q Command to force replication of Active Directory
Answer: c:\Dfsrdiag PollAD (This command should be run on the Destination server)

Q Utility to Force Sysvol Reaolication in 2003/2000
Answer: ntfrsutl forcerepl [Computer] /r [SetName] /p [DnsName]

Q To force Sysvol Replication ?
Answer: Restart FRS Service

Q What is DFSR ?
Answer: SYSVOL replication using DFS is called DFS-Replicated SYSVOL (DFSR)

ISTG (Inter Site Topolgy Generator)

ISTG:


Q What is ISTG ?
Answer: ISTG is nothing but a KCC server(DC), which is responsible for reviewing the inter-site topology and creating inbound
replication connection objects as necessary for bridgehead servers in the site in which it resides.The domain controller holding this role may not necessarily also be a bridgehead server.

Q TO generate the replication topology on the ISTG:
1> Determine the server that holds the ISTG role for the site. 
2> Open Active Directory Sites and Services: On the Start menu, point to Administrative Tools, and then click Active Directory Sites and Services. 
3> In the console tree, expand Sites, and then expand the site that contains the ISTG on which you want to run the KCC. 
4> Expand Servers, and then click the Server object for the ISTG. 
5> In the details pane, right-click NTDS Settings, click All Tasks, and then click Check Replication Topology. 
6> In the Check Replication Topology message box, click OK.

Q To generate Intersite replication topology?
A To generate the intersite replication topology, run the KCC on the domain controller in the site that holds the ISTG role.
Q To generate Intrasite replication topology ?
A To generate the intrasite replication topology, run the KCC on any domain controller in the site that does not hold the ISTG role.

Q Event 1009
A Event 1009 (informational): The consistency checker has started updating the replication topology for this server.

Q Event 1013
A Event 1013 (informational): The replication topology update task terminated normally.

Q How to increase Logging Level in KCC? What are it's merits & demerits ?
A The KCC, like all subsystems in Active Directory, has a variable event logging level. By default, only the most important events are logged. You can increase the level of detail in the event log by modifying the value in the Replication Events entry in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Diagnostics in the registry.
Increasing the level of detail can be used to better understand the behavior of the KCC in different situations. However, a logging level value of greater than 2 generally results in excessive logging that degrades the performance of the component. Increasing the logging level can be useful for troubleshooting problems, but it is not recommended for normal operation

Q Intervals at whic KCC runs ?
A * 5 mins after the domain Controller starts: By default, the KCC runs its first replication topology check five minutes after the domain controller starts. This interval can be modified by changing the Repl topology update delay (secs) entry in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters as follows:
Value: Number of seconds to wait between the time Active Directory starts and the KCC runs for the first time.
Default: 300 seconds (5 minutes)
Data type: REG_DWORD
* services are running, the KCC checks the topology every 15 minutes : By default, as long as services are running, the KCC checks the topology every 15 minutes and makes changes as necessary. The administrator can modify the interval at which the KCC performs this review by changing the Repl topology update period (secs) entry in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters as follows:
Value: Number of seconds between KCC topology updates
Default: 900 seconds (15 minutes)
Data type: REG_DWORD

Q What happen if Current ISTG becomes unavailable ?
A If the current ISTG becomes unavailable for 60 minutes, an election is held by the other DCs in the site to appoint a new ISTG. This can sometimes cause problems for Active Directory replication

Q Default time for ISTG to establish new connection automatically between 2 sites if Primary ISTG server of either site fails ?
A 60 min

Q Mandatory Requirement for ISTG to be transferred to another server?
A It should be ADC(Additional Domain Controller)

Q To transfer ISTG role frm DC to other other Servers ?
A Open ADSIEDIT.msc
  1. Expand Configuration [DomainController].
  2. Expand CN=Configuration,DC=<domain>,DC=<com>.
  3. Expand CN=Sites.
  4. Highlight CN=<sitename> for the site where you want to change the ISTG Server.
  5. In the details pane, right-click on CN=NTDS Site Settings and select Properties.
  6. Locate the interSiteTopologyGenerator attribute and you will see which Domain Controller is designated as the ISTG server.
  7. To change the server, click Edit and then change the server name

Q To verify the replication ?
A repadmin /showrepl <servername> /u:<domainname>\<username> /pw:*

Group Policy Interview & Assessment Questions

Group Policy:
Q To whom Group Policy Objects are Linked in Active Directory ?
A Group Policy objects are linked to site, domain, and OU containers in the Active Directory

Q What's the default order of precedence ?
A The default order of precedence follows the hierarchical nature of the Active Directory: sites are first, then domains, and then each OU.

Q Which would be processed first ?
A OU would be processed first because it contains USERS Configurations & Computer Configurations Profiles

Q Between Computer Policy & User Policy Which Would be Processed first?
A Computer Policy would be processed first in the Order Specified by Normal group Policy Processing. But if there is Conflict between Computer Policy & User Policy then User Policy would be processes first because user policy preocesses in seconds

Q Which Policy in Group Policy Changes the default processing Order ?
A Loopback Policy Processing order.

Q Modes of Loopback Processing ?
A Two Modes: Merge & Replace
Merge:- User based Policies & Machine based Policies both are applied to the Machine
Replace:- Only Machine Policies are applied

Q What is the use of Group Policy Modeling wizard ?
A: Predict what the Effective Policy would be.

Q what is the use of Group Policy Results Wizard ?
A: Tell us what the actual effective Policies are.

Q Modes of RsoP(Resultant Setup of Policy)
Answer: Two Modes: Logging & Planning Mode
Logging – Maps to the Group Policy results wizard
Planning Mode:- Maps to the Group Policy Modeling wizard

Q Where the base of ADMX File is stored ?
Answer: PDC Emulator

Q Can GPO be associated with more than One Active Directory Container ?
A Yes, A GPO can be associated with more than one Active Directory container

Q Can Multiple Containers be linked to single GPO ?
A Yes, multiple containers can be linked to a single GPO

Q IF more than One GPO is Linked to the Active Directory Container then What would be the processing priority ?
A The GPO link with the lowest link order in the Group Policy Object Links list has precedence by default. However, if one or more GPO links have the Enforced option set, the highest GPO link set to Enforced takes precedence.

Q What is the difference between the Actual Group Policy Objects & Group Policy Link Objects
A: Status Tab is displayed in the Actual Group Policy Objects but not in Link

Q Difference Between Enforced & Block Inheritance ?
A Enforced(No Override) is a link property, and Block Policy Inheritance is a container property. Enforced takes precedence over Block Policy Inheritance.

Q Group Policy Configuration for WSUS ?
A Computer Configuration -> Policies-> Administrative template-> Windows Component -> Windows Update -> Configure Automatic Updates, Specify Intranet Microsoft Service Update Location

Q HTTP Port No of WSUS
A 8530

Q GPO Blocking(Facebook)
A User Configuration-> Policies -> Windows settings-> Internet explorer Maintenance-> Security-> Security Zones and Content Rating->Properties-> Select Import Current Content Rating setttings-> Modify->Approved Sites-> Enter Site Name-> Never

Q What are the key Characteristics of GPO Processing ?
Answer: Policy Processing Sequence can be controlled using loopback processing
User Configuration settings take precedence over Computer Configuration settings

Q Order in which Group Policy Objects are Processed
Answer: Local GPO
Site GPO
Domain GPO
OU GPO
Child OU GPO

Q What factors should be considered when defining the security groups that will be delegated administrative control of all or part of the OU ?
Answer: The type of group to be deployed within a forest
The Location of the OU's within the forest
The number of departments requiring autonomous control over their Own OU Structure

Q Need to use Group Policy Caching in your Active Directory ?
Answer: It can reduce the time it takes to process the policy
The policy is for remote computers with a latent connection

Q Command to display All available Information in Group Policy ?
Answer: gpresult /z

Q Command to display the Results in Group Policy ?
Answer: gpresult /r

Q Command to force gpresult to overwrite the filename of the output filename ?
Answer: gpresult /f

Q Command to specify Output file is n HTML ?
Answer: gpresult /h

Q To make sure that Users settings must be processed before computer settings in a public Area ?
Answer: Enable Loopback processing

Q To fix Group Policy settings are using a lot of home bandwidth
Answer: Enable slow link detection

Q Desktop background Images are being reset everyday?
Answer: Do not specify that a policy must be processed even if not changed.

Q File type in which Group Policy Object, security configuration settings are stored ?
Answer: .inf

Q How does Group Policy Object, or GPO, Security Filtering Affect. How Group Policy is processed in Windows Server 2012 R2 ?
Answer: In Absence of GPO filtering, by default, GPO is applied to all authenticated objects
It applies specific Group Policy to Individual Security Principals

Q What are the Configuration Options for software installation policy ?
Answer: Assign to Computer
Assign to Users On-Demand
Assign to Users

Q To obtain the Resultant Set of Policy for a Computer that is not currently authenticated, Which mode need to be deployed using Group Policy Modelling Wizard ?
Answer: Planning Mode
Active Directory: 
Active Directory Schema:

The Active Directory Schema acts as as blue print for ADDS by Defining the Attributes, Objects & Classes.



Contents of Attribute:
1> ObjectSID
2> sAMAccount Name
3> Location
4> Manager
5> Department


Contents of Classess:
1>User
2>Group
3>Computer
4>Site


Contents of Objects:
1> User Names
2> Computer Names


Active Directory Snapshots:



To List, Mount& Create Active Directory Snapshots:
1> ntdsutil
2> ntdsutil:activate instance ntds
Active instance set to “ntds”
ntdsitil:snapshot
snapshot:
3> List all Previous snapshots:
snapshot: list all
4> List Mounted snapshots:
snapshot: list mounted
5> List all other options:
snapshot: help
6> To create snapshot: (Take the snapshot of the current Active Directory Instance)
snapshot: create
7> To Mount the snapshot:
snapshot: mount 5 (Example: 5- is the snapshot ID)
8> snapshot: quit
9> ntdsutil: quit
10> Specify the path of the snapshot containing ntds.dit:
dsmain -dbpath C:\$NAP…….\Windows\NTDS\ntds.dit -ldapPort 51839
Tests in FailOver Cluster Validations:


Tests in Cluster Validation
  • HYPER-V(Available Only if HYPER-V Role is installed)
  • Cluster Configuration(Available only if a cluster is running)
  • Inventory
  • Network
  • Storage
  • System Configuration

Q Tests under Inventory in Cluster Validation.'
A Inventory:
Storage:
List Fibre Channel Host Bus Adapters
List iSCSI Host Bus Adapters
List SAS Host Bus Adapters
System:
List BIOS Information
List Environment Variables
List Memory Information
List Operating System Information
List Plug and Play Devices
List Running Processes
List Services Information
List Software Updates
List System Drivers
List System Information
List Unsigned Drivers


Q Tests under Network in Cluster Validation ?
A Network
List
Network Binding Order
Validate
Cluster Network Configuration
Validate
IP Configuration
Validate
Network Communications
Validate
Windows Firewall Configuration

Q Tests under Storage in Cluster Validation ?
A Storage
List Disks
List Potential Cluster Disks
Validate CSV Network Bindings
Validate CSV Settings
Validate Disk Access Latency
Validate Disk Arbitration
Validate Disk Failover
Validate File System
Validate Microsoft MPIO-Based Disks
Validate Multiple Arbitration
Validate SCSI device Vital Product Data (VPD)
Validate SCSI-3 Persistent Reservation
Validate Simultaneous Failover
Validate Storage Spaces Persistent Reservation

Q Tests under SystemConfiguration in Cluster Validation ?
A System Configuration
Validate Active Directory Configuration
Validate All Drivers Signed
Validate Memory Dump Settings
Validate Operating System Edition
Validate Operating System Installation Option
Validate Operating System Version
Validate Required Services
Validate Same Processor Architecture
Validate Service Pack Levels
Validate Software Update Levels

Q Tests Under Cluster Configuration in Cluster Validation ?
A Cluster Configuration (available only if a cluster is running)
o List Cluster Core Groups
o List Cluster Network Information
o List Cluster Resources
o List Cluster Volumes
o List Clustered Roles
o Validate Quorum Configuration
o Validate Resource Status
o Validate Service Principal Name
o Validate Volume Consistency

Q Tests under HYPER-V in Cluster Validation ?
A Hyper-V (available only if the Hyper-V Role is installed)
o List Hyper-V Virtual Machine Information
o List Information About Servers Running Hyper-V
o Validate Compatibility of Virtual Fibre Channel SANs for Hyper-V
o Validate Firewall Rules for Hyper-V Replica Are Enabled
o Validate Hyper-V Integration Services Version
o Validate Hyper-V Memory Resource Pool Compatibility
o Validate Hyper-V Network Resource Pool and Virtual Switch Compatibility
o Validate Hyper-V Processor Pool Compatibility
o Validate Hyper-V Role Installed
o Validate Hyper-V Storage Resource Pool Compatibility
o Validate Hyper-V Virtual Machine Network Configuration
o Validate Hyper-V Virtual Machine Storage Configuration
o Validate Matching Processor Manufacturers
o Validate Network Listeners Are Running
o Validate Replica Server Settings

FailOver Clustering (Windows):

Disk Witness & File Sharing Witness:
 
Why Disk-witness is better than File-Share Witness ?

Disk-Witness is preffered over File-Share Witness because Disk-Witness solves partition-in-time & File-Share Witness prevents partition-in-time Occuring





 
Difference between Disk-Witness & File-Share Witnes:
Disk-Witness
File-Share-Witness
Not used in Multi-Site Clustered
Used in Multi-Site Clusters because there wouldn't be shared storage between the two sites
Should be used where shared storage is available.
File-share witness should be placed in a third site to provide protection from a site failure.
Disk-Witness solves partition-in-time
File-Share Witness prevents partition-in-time Occuring


File Sharing Witness: 

File Sharing-Witness doesn't Contain replica of cluster configuration. 

It contains only Information that previous running node has most recent replica which have turned-off just now. So, To start cluster with other second node the previous node should be turned on or Node 1 can only be turned off when second node is started and running.

Contents Under File Sharing Witness:


Folder named with GUID of Cluster. 

In that folder, two files are created:
VerifyshareWriteAccess.txt
Witness.log



 
Vmware Interview Questions & Assessments:

Q What are the different types of Partitions in ESX server?
Answer: / -root
Swap
/var
/Var/core
/opt
/home
/tmp


Q What are the three port groups present in ESX server networking
A 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 is the use of a Port Group?
A The port group segregates the type of communication.

Q What are the type of communications which requires an IP address for sure ?
A Service Console and VMKernel (VMotion and iSCSI), these communications does not happen without an ip address (Whether it is a single or dedicated)

Q . In the ESX Server licensing features VMotion License is showing as Not used, why?
A Even though the license box is selected, it shows as “License Not Used” until, you enable the VMotion option for specific vSwitch


Q What are the core services of VC(V Center) ?
A VM provisioning , Task Scheduling and Event Logging


Q Does cloning from template happens between two datacenters ?
A Yes.. it can, if the template in one datacenter, we can deploy the vm from that template in another datacenter without any problem.

Q . What are the situations which triggers vMotion automatically?
A * Resource Contention between virtual machines (DRS)
    * Distributed power management


Q. What is VMWare consolidated backup ?
Answer: It is a backup framework, that supports 3rd party utilities to take backups of ESX servers and Virtual Machines. Its not a backup service.


Q What are the moduleds that are noy pre-installed must be added to Vcenter ?
Answer: Following modules that are not pre-installed must be added to Vcenter:
1> Vmware vCenter Converter
2> Vmware vCenter Guided Consolidation
3> Vmware vCenter Update Manager

Q Whattasks can be selected from the home page of an ESX Server ?
A The graphics shows the following tasks can be selected from the home page:
1> Download VMware vCenter
2> Browse Datastores in this Host's inventory
3> Browse Objects Managed by this Host

Q How are new LUNs discovered by an ESX Host?
A A rescan operation is required every time a new LUN is added

Q What makes iSCSI and FC diffrent ?
Answer: 1> A ddressing Scheme: iSCSI relies on IP and FC not
2> Type of transfer of data: In FC, the data transferred as blocks, in iSCSI the data transferred as files.
3> Cabling : FC uses Fibre cable and iSCSI uses RJ45.

Q What is the format for iSCSI addressing ?
Answer: IP Address

Q How we can list pNICs & status using command line ?
Answer: ifconfig –a

Q What is the Maximum Host Failure allowed in a cluster
Answer: 4

Q How does HA know to restart a VM from a dropped Host
Answer: storage lock will be removed from the metadata

Q .How many iSCSI targets will ESX support
Answer: 8 for 3.01, (64 for 3.5)

Q How Many Fiber Channel targets
Answer: (256) (128 on Install)

Q What is Vmotion
Answer: ability to move running vm from one host to another

Q Does HA use vmotion?
Answer: the answer is no – vm stops and restarts on ESX other host

Q What is the maximum number of paths allowed in ESX 4.x for an iSCSI LUN?
Answer: 8

Q What is the maximum number of paths allowed in ESX 4.x for an NFS?
A: 8

Q Which steps is required for iSCSI software multipathing, must be performed using the esxcli interface?
Answer: Connecting the iSCSI software initiator to the VMkernel ports

Q Which CHAP Authentication mechanisms is available when using Software iSCSI, but not Hardware iSCSI?
Answer: Per-Subnet CHAP & Mutual CHAP

Q Which components must be modified in order to enable Jumbo Frame support for the Software iSCSI Initiator ?
Answer: The VMkernel port & The virtual switch

Q Using Hardware iSCSI Initiators with ESX/ESXi hosts allows which tasks to be offloaded from the Vmkernel ?
Answer: 1> Encapsulation of I/O requests into iSCSI Protocol Data Units (PDUs)
                2> Encapsulation of iSCSI PDUs into TCP/IP packets

Q An ESX Host gains exclusive access to Virtual Machines created on NFS datastores using:
Answer: A special .lck-XXX lock file

Q What is the default port used by iSCSI in a VMware vSphere environment?
A 3260

Q What are the common issues with snapshots? What stops from taking a snapshot and how to fix it ?
Answer: 1> 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.
2> If you configure the VM with Mapped LUN’s as physical, you need to remove it to take a snapshot.
Q What is the maximum configurable number of NFS datastores that can be mounted to an ESX/ESXi 4 Host?
A 64

Q How many service console ports can be created in ESX ?
A 16

Q What is the maximum number of suported paths allowed in ESX/ESxi ?
A: 1024

Q Maximum number of LUNs that can be attached to a host (ESXi 5.0)
Answer: 256

Q Maximum number of vCPUs that can be assigned to a VM (ESXi 5.0)
Answer: 32

Q What is the maximum number of hosts per HA cluster?
Answer: Maximum number of hosts in the HA cluster is 32

Q What is maximum number of primary HA hosts in vSphere 4.1?
A Maximum number of primary HA host is 5. VMware HA cluster chooses the first 5 hosts that joins the cluster as primary nodes and all others hosts are automatically selected as secondary nodes
Q What is the maximum number of cores that can be used with Standard licensing?
Answer: 6

Q Additional licensing is required once the number of cores per CPU reaches
Answer: 8 or more cores

Q In vSphere, a bound physical NIC can be configured to transmit and receive Jumbo Frames. What is the Maximum Transmission Unit (MTU) for Jumbo Frames in vSphere?
Answer: 9000

Q What features can be used in combination with Network Attached Storage ?
Answer: 1> VMware HA
2> Virtual Machine Snapshots
3> Storage Vmotion

Q Which vSphere Editions include VMware Data Recovery ?
A VMware Data Recovery is available in Essentials Plus for Retail, Advanced, Enterprise & Enterprise Plus

Q Before you upgrade an ESXi host?
Answer: 1> Back up the host configuration before you begin a host upgrade: save the ESXi configuration using vicf g-cfgbackp s from the vCLI.
2> Verify current hardware is supported per the vSphere Systems Compatibility Guide.
3> Compare the md5sum of the downloaded file to the value on the VMware download website.
4> Run the VMware CPU Identification Utility
Q On ESX/ESXi hosts, VMware HA needs and automatically opens the following firewall ports.
Answer: Incoming port: TCP/UDP 8042-8045
Outgoing port: TCP/UDP 2050-2250

Q When you delete a VMFS datastore, it is destroyed and disappears from:
Answer: All hosts with connectivity to the datastore

Q The Challenge Handshake Authentication Protocol (CHAP) is used with iSCSI on an ESX Server to provide :

Answer: Initiator authentication

Q Valid software iSCSI initiator in ESX 3 ?
Answer: vmhba32

Q Which two discovery options does the vSphere Client offer when setting up the iSCSI initiator?
Answer: Static & Dynamic

Q What is the default number of ports configured with the Virtual Switch?
Answer: 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 Which functions cannot be performed remotely and must be performed from the ESXi Direct Console ?
Answer: 1> Restart Management Agent
2> Test the Management Network
3> Restore a Standard Switch

Q An administrator is unable to connect a vSphere client to an Esxi host. Which of the following options can be selected from Direct Console to restore connectivity without distrupting running virtual Machnies ?
A> Restore the Standard switch
B> Restart the Management Network
C> Restart Management Agent
D> Delete the Management Network
Ans: Restart Management Agent

Q What are the security options available for ESX vswitch?
Answer: Promiscuous Mode – Reject
MAC Address changes – Accept
Forged Transmits – Accept

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