Interview Q&A

Salary check:

One of the important thing is to know the job market, the salary the company provides. Check the below sites who provides the salary comparisons  Payscale.com, Glassdoor.com, Salary.com

Record interview conversation:

Use your phone to record voice during Interview sessions so that you can playback it later and note down the questions. These questions will be useful for attending other interviews.

I have tried the Interview mode in voice recorder in Samsung Galaxy S6 edge. To be honest, it is not very good in capturing interviewer’s voice. I placed my phone on my shirt pocket. Just go with normal voice recorder.

If it is telephonic interview and if you have Android phone you can use Automatic Call Recorder. It automatically records call and there is no ‘beep’ sound you normally get in Symbian phone era.

https://play.google.com/store/apps/details?id=com.appstar.callrecorder&hl=en

Foreign jobs:

Don’t pay any upfront fee (such as for background verification, VISA processing, Bank guarantee etc). Even if they say the amount can be reimbursed when you join. This is usually a fraud.

  • Make sure the company has landline number.
  • Make sure the company can be searched in Google and other sites (Glassdoor reviews etc)
  • Make sure the company can be physically located. You can ask your friends in those countries to verify this.

Examples:

https://forum.singaporeexpats.com/viewtopic.php?f=15&t=115529

https://www.hcisingapore.gov.in/pages.php?id=660


Synechron Interview Question for Windows administrator

0. Tell about yourself.

1. What are the new features in PowerShell version 5

In PowerShell 5 there are improvements in Desired State Configuration, security, performance, remoting, and language enhancements.

Windows PowerShell 5.0 is backward-compatible. Cmdlets, providers, modules, snap-ins, scripts, functions, and profiles that were designed for Windows PowerShell 4.0, Windows PowerShell 3.0, and Windows PowerShell 2.0 generally work in Windows PowerShell 5.0 without changes.

Windows PowerShell 5.0 is installed by default on Windows Server® 2016 and Windows 10®. To install Windows PowerShell 5.0 on Windows Server 2012 R2, Windows 8.1 Enterprise, or Windows 8.1 Pro, download and install Windows Management Framework 5.0.

2. Different memory management techniques in VMware ?

Memory ballooning

Memory Ballooning is the memory reclamation technique used by hypervisor to reclaim the memory back from the virtual machine. Ballooning will happen on the ESXi host which is running out of physical memory or its memory state is soft.

More details: http://www.vmwarearena.com/vmware-memory-management-part-3-memory-ballooning/

Hot swapping

VMware supports addition or removal of CPU and RAM on ESXI while the ESXI and VMs are still running.

You can see whether this feature is available or not for a VM in VMware Vcenter -> VM -> Edit settings -> Options -> Memory / CPU Hotplug. The VM needs to be in powered off state to enable or disable this.

cpu-memory-hotswap

Shared memory

All the VMs in VMware or Hyper-V shares the ESXi memory and CPU. That said we can reserve CPU and Memory for a particular VM in Vcenter.

3. What is HA slot in VMware ?

Cluster settings vSphere HA is used to reserve ESXi resource such as CPU and RAM. This is needed for High availability (HA).

HA is needed to migrate VMs from failed ESXi to live ESXi hosts. This is accomplished through vMotion.

ha-slot

4. What are the FSMO roles and which one is most important ?

FSMO – Flexible Single Master Operations. Schema, Domain Naming Master, RID Master, PDC Emulator and Infrastructure Master comprises FSMO roles.

so which one is important ?

PDC emulator role is important. PDC Emulator – Primary Domain Controller Emulator.

1. It acts a time synchronizer for all the domain controllers.

2. Password changes, Account Lockouts are always replicated to PDC Emulator from Domain controllers.

3. PDC Emulator should be available when creating or modifying Group Policies.

5. What are the different active directory partitions ?

Partitions are a logical way of representing AD. There are 4 partitions.

Schema

Configuration

Domain

Application

First 3 partitions are native AD partitions. More details here:

https://theamvj.wordpress.com/ad/

6. What information is stored in configuration partition ?

Forest and domain trust relationship details are stored in Configuration partition.

7. where is the active directory database is stored ?

C:\Windows\NTDS\NTDS.DIT is where the AD database is stored.

8. What is conditional forwarder in DNS ?

A Conditional Forwarder is a DNS server forwards DNS queries to external DNS servers (which are not resolvable within the internal network) for external DNS name resolution outside the network (Internet).

By using a forwarder, we can resolve names that are outside our network, such as names on the Internet.

9. What are the different DNS records ?

A, AAAA, CNAME, MX, NS Records are some of the DNS records.

Address Mapping records (A)

The record A specifies IP address (IPv4) for given host. A records are used for conversion of domain names to corresponding IP addresses.

IP Version 6 Address records (AAAA)

The record AAAA (also quad-A record) specifies IPv6 address for given host. So it works the same way as the A record and the difference is the type of IP address.

Canonical Name records (CNAME)

The CNAME record specifies a domain name that has to be queried in order to resolve the original DNS query. Therefore CNAME records are used for creating aliases of domain names. CNAME records are truly useful when we want to alias our domain to an external domain. In other cases we can remove CNAME records and replace them with A records and even decrease performance overhead.

Mail exchanger record (MX)

The MX resource record specifies a mail exchange server for a DNS domain name. The information is used by Simple Mail Transfer Protocol (SMTP) to route emails to proper hosts. Typically, there are more than one mail exchange server for a DNS domain and each of them have set priority.

Name Server records (NS)

The NS record specifies an authoritative name server for given host.

Reverse-lookup Pointer records (PTR)

As opposed to forward DNS resolution (A and AAAA DNS records), the PTR record is used to look up domain names based on an IP address.

Start of Authority records (SOA)

The record specifies core information about a DNS zone, including the primary name server, the email of the domain administrator, the domain serial number, and several timers relating to refreshing the zone.

Text records (TXT)

The text record can hold arbitrary non-formatted text string. Typically, the record is used by Sender Policy Framework (SPF) to prevent fake emails to appear to be sent by you.

10. What is Stub zone ?

Stub zone is used to resolve names between different DNS namespaces. A stub zone is a copy of a zone that contains only resource records that are necessary to identify the authoritative DNS servers for that zone.

A stub zone is used to resolve the host names of other internal Domain within the company or other company (for ex: say we have acquired).

Stub zone consists of:

  • Start of Authority (SOA) record
  • Name server (NS) record
  • A record

11. What is CNAME ?

CNAME – Canonical Name. CNAME is one of the DNS record. CNAME records can be used to alias one name to another

For example, if you have a server where you keep all of your documents online, it might normally be accessed through docs.example.com. You may also want to access it through documents.example.com. One way to make this possible is to add a CNAME record that points documents.example.com to docs.example.com. When someone visits documents.example.com they will see the exact same content as docs.example.com.

12. What is the difference between forward lookup zone and reverse lookup zone ?

Forward lookup zone

A Forward lookup zone host names to IP addresses mappings.

Reverse lookup zone

A Reverse lookup zone contains IP address to host name mappings.

Reverse lookups are possible because of a special domain called the in-addr.arpa domain, which provides a separate fully qualified domain name for every possible IP address on the Internet.

To enable a reverse lookup for a particular IP address, all you have to do is create a PTR record in a reverse lookup zone (a zone that is authoritative for a portion of the in-addr.arpa domain). The PTR record maps the in-addr.arpa domain name for the address to the host’s actual domain name.

13. What is the difference ping and nslookup ?

A ping is used to check the connectivity and network latency for a remote server.

Nslookup is used to check Name server

14. What is the difference between ping -a and nslookup ?

Ping -a -> Resolves address to hostname

nslookup -> Provides DNS server details of the current machine

nslookup <> -> Provides the host name of the IP address

15. What are the challenging issues you faced in the last 6 months ?

Implementing Altiris patching tool – working with Networking team to allow ports, adding host name and IPs in hosts file.

Configuring servers in PowerAdmin monitoring tool

16. Can you explain the patching process you follow in your concern ?

I take of Windows server patching in our environment. Every month second Tuesday, Microsoft release patches. We have a Patch Review Board team which consists of System Team, Security Team and other Principal level DEV / QA members who review the list of patches. Patches that are irrelevant are removed.

Then the system team tests the patches on a set of servers. Once it is successful, those patches are approved.

Approved patches are initially installed to Staging servers and then production.

Similarly in DEV / QA patches are initially installed on workstations followed by less critical and then to critical servers.

17. Scenario based question. What is the procedure do you take if you want to patch a server that is not patched for the past 2 years ?

If it is a Virtual Machine, better take a clone of the server and snapshot is not recommended. Usually servers that are not patched for 2 years takes time to come up. I have seen servers taken 1 – 1.5 hrs to come up after restart. Also to install all the 2 years of patches, multiple restart would be required.

If it is a physical box, try to do a P2V before doing patching if possible. This is only possible if you have a VM environment.

18. What is your experience working in server operations team ?

List the experience

Kind of work in lab / datacenter environment – addressing HDD, RAM, Server, Power and other Hardware issues.

Working with vendors such as VMware, NetApp to resolve issues etc.

19. Scenario based question, you have a server in US and a UK person is unable to RDP the server. How will you figure out and resolve the issue ?

  • Make sure there is no network issue. Check the server is accessible via Ping.
  • If the server is up, make sure Firewall is not blocking, hope RDP is enabled on the server.
  • Make sure you are able to Telnet to the server with the RDP port (3389 – TCP and UDP) ex: telnet <> 3389
  • If the above two are not having any issues, and if it is a VM, try to open the console and check whether the server is accessible.

20. How can you know / view the servers that have FSMO roles ?

Open command prompt and type the following command (either in Domain controller or servers that are joined in Domain):

NetDOM /query FSMO

This will list all the 5 FSMO roles with servers associated with them.

21. What are the services constitutes Remote Desktop (RDP) ?

Its Remote desktop services in services.msc that needs to be running.

———————

Vodafone Interview Questions for Windows VMware administrator

1. What are your day-to-day activities?

2. How will you trouble shoot a server hang issue? What will be the steps if it is a Domain controller or a normal member server?

There are 2 types of hang: Hard hang and soft hang.

Hard hang: You can identify this when you keyboard becomes not responsive. Numlock, Capslocks keys are not responsive. This is due to hardware issues. The system is hung at a very low level in the kernel and is no longer processing threads. Try Hardware diagnostic tools to run at startup level. Try to remove and connect RAM, HDD and cables.

Soft hang:

Microsoft Debug Diagnostic Tool

The Microsoft Debug Diagnostic Tool (DebugDiag) is designed to assist in troubleshooting issues such as hangs, slow performance, memory leaks or memory fragmentation, and crashes in any user-mode process.

3. What are the troubleshooting steps in case of a physical Windows server that is completely freeze or hanged?

After reboot or once it is up, we can use Microsoft’s debug diagnostics (Free) tool to check for issues.

Also Event viewer

4. What are the inbuilt OS tools you use to identify that causes the hang / freeze issues?

Reliability Monitor. Inbuilt tool.

https://theamvj.wordpress.com/2017/02/08/reliability-monitor/

5. What are the inbuilt OS tools that you can use to identify that causes hang / freeze issues on remote physical machine?

6. What is Poolmon?

Microsoft Pool monitor application is used to check Kernel Memory leaks.

Poolmon displays data that the operating system collects about memory allocations from the system paged and nonpaged kernel pools and about the memory pools used for Terminal Services sessions.  This information can be used by Microsoft Technical Support to find kernel mode memory leaks.

Memory leak

A memory leak occurs when a process allocates memory from the paged or nonpaged pools, but does not free the memory. As a result, these limited pools of memory are depleted over time, causing Windows to slow down. If memory is completely depleted, failures may result.

A memory leak is caused by an application or by a process that allocates memory for use but that does not free the memory when the application or process finishes. Therefore, available memory is completely used over time. Frequently, this condition causes the system to stop functioning correctly.

https://support.microsoft.com/en-us/kb/177415

7. What is the difference between page-pool and non-page-pool memory?

  • The non-paged pool consists of virtual memory addresses that reside in physical memory.
  • The paged pool consists of virtual memory that can be paged in and out of the system.
  • The memory manager creates the following memory pools that the system uses to allocate memory: non-paged pool and paged pool.
  • Both memory pools are located in the region of the address space that is reserved for the system and mapped into the virtual address space of each process.

8. What is a Virtual memory? Where does the virtual memory data get saved in HDD?

Pagefile.sys is where the Virtual memory data is saved.

9. How will you troubleshoot Bluescreen error?

Microsoft Reliability Monitor, Debug Diagnostics and Nirsoft’s Bluescreen view.

10. How will you configure Dump file in Windows?

My Computer -> Properties -> Advanced -> Startup and Recovery -> Settings -> Dump file: %SystemRoot%\MEMORY.DMP

11. What are the prerequisites or things you need to consider for configuring Dump file in Windows?

Make sure the Drive has adequate amount of free space

12. In case if a machine did not boot up in normal mode what will you do?

Options are by pressing F8 during boot:

  • We have last known good configuration (LKGC)
  • Start it in safe mode and run chkdsk /r

13. What are the advanced menu options available during bootup (like F8)?

For Windows 7 and older:

  • Safe mode
  • Safe mode with network
  • Directory Services Restore mode (in case of Domain controller)
  • Start with last known Good configuration

Windows 8 and above

win-8-and-10-options

14. What do you understand by NTDSUTIL or what are its uses?

  • NTDSUTIL is used to seize FSMO roles from one Domain controller and give it to another Domain controller.
  • Also it is used to change AD Directory services restore mode password

dsrm

http://www.top-password.com/knowledge/reset-directory-services-restore-mode-password.html

15. What are the FSMO roles?

  • Schema Master
  • Domain Naming Master
  • Infrastructure Master
  • PDC Emulator
  • RID Master

16. What are the information stored in SYSVOL folder?

SYSVOL – System Volume. This folder can be only created on NTFS partition. It contains:

  • Group policy settings
  • GPO templates
  • Logon scripts

The contents in the SYSVOL folder are replicated to other domain controllers using File Replication Service and Distributed File System Replication Service.

17. What is the port number for Terminal services (RDP), FTP, and DNS?

  • RDP – 3389
  • FTP – 20, 21
  • DNS – 53

18. What are the prerequisites for vMotion?

A virtual machine and its host must meet resource and configuration requirements for the virtual machine files and disks to be migrated with vMotion in the absence of shared storage.

vMotion in an environment without shared storage is subject to the following requirements and limitations:

  • The hosts must be licensed for vMotion.
  • The hosts must be running ESXi 5.1 or later.
  • The hosts must meet the networking requirement for vMotion.
  • The virtual machines must be properly configured for vMotion.
  • Virtual machine disks must be in persistent mode or be raw device mappings (RDMs).
  • The destination host must have access to the destination storage.
  • When you move a virtual machine with RDMs and do not convert those RDMs to VMDKs, the destination host must have access to the RDM LUNs.
  • Consider the limits for simultaneous migrations when you perform a vMotion migration without shared storage. This type of vMotion counts against the limits for both vMotion and Storage vMotion, so it consumes both a network resource and 16 datastore resources. See Limits on Simultaneous Migrations in the vSphere Web Client.

19. What is a Snapshot? Why do we take a Snapshot?

A Snapshot captures the state of a VM. Snapshot can be used to revert the state of the VM. This is helpful while we make any changes to the VM but we are not sure about the result.

Snapshot should not be taken for VMs that are having high I/O such as Database servers. VMware recommends not to keep snapshot for more than 3 days. VMware recommends a maximum of 32 Snapshots per VM.

20. What is the difference between Windows 2003 and Windows 2008 Boot order?

In Windows 2003, NTDLR reads boot.ini and loads the OS. Boot.ini, NTLDR and NTDETECT.com are the boot files in Windows 2003.

Windows Vista and later operating systems replaced the NTLDR with the Windows Boot Manager (BOOTMGR). The BOOTMGR file is located in the 100 MB system partition automatically created during the Window 7 and Server 2008 R2 installation.

Once a system is started, Boot sector loads BOOTMGR -> Which looks for Boot Configuration Database (BCD) -> BCD contains boot configurations.

To edit BCD, we need to use BCDEdit

System Reserved contains the Boot files (Bootmgr, BCD)

disk-mgmt-on-windows-2008-r2-server

21. In Windows 2008, there is no boot.ini. What is replaced with Boot.ini?

Boot.ini does not exist in Windows 2008. All boot configuration are in Boot Configuration Data (BCD) store.

Boot Configuration Data (BCD) store contains boot configuration parameters and controls how the operating system is started in Microsoft Windows Vista and Microsoft Windows Server 2008 operating systems.

Bcdedit.exe

You can use Bcdedit.exe to modify the Windows code which runs in the pre- operating system environment by adding, deleting, editing and appending entries in the BCD store. Bcdedit.exe is located in the \Windows\System32 directory of the Windows Vista partition.

bcdedit-command

What can I do with Bcdedit.exe?

Bcdedit.exe currently enables you to do the following:

  • Add entries to a existing BCD store
  • Modify existing entries in a BCD store.
  • Delete entries from a BCD store.
  • Export entries to a BCD store.
  • Import entries from a BCD store.
  • List currently active settings.
  • Create a BCD store for a later installation of Windows Server 2008.
  • Apply a global change (to all the entries).
  • Change the default time-out value.

22. We cannot edit boot.ini file in Windows 2008. We have to use BCDEdit command to edit boot order in Windows 2008.

bcdedit-command

23. What are the troubleshooting steps if you are unable to delete a folder? Also while trying to delete you are getting error file is in use error.

We need to check with Process Explorer or Handle command line utility.

24. What is Open handles?

Open handle is simply a file has been marked as opened for either Read or Write access.  Any application or process running on the server can have any number of open handles.

Sometimes application programmers forget to close handles that they have open to files and programically open multiple handles to the same file.  When this happens it is causes what is commonly referred to as a handle leak.

Servers depending on their hardware and software being used can handle a limited number of handles.  So an application that had a handle leak will cause problems if it causes the server to reach its handle limit.

Utilities available for Handle issues:

  • Handle v4.1 (Command line)
  • Process Explorer (GUI)

You can find Microsoft’s utility – Handle v4.1

Handle is a utility that displays information about open handles for any process in the system. You can use it to see the programs that have a file open, or to see the object types and names of all the handles of a program.

https://technet.microsoft.com/en-us/sysinternals/handle.aspx

https://technet.microsoft.com/en-us/sysinternals/processexplorer

25. What is process explorer?

Process Explorer shows you information about which handles and DLLs processes have opened or loaded.

Process Explorer is useful for tracking down DLL-version problems or handle leaks, and provide insight into the way Windows and applications work.

https://technet.microsoft.com/en-us/sysinternals/processexplorer.aspx

26. What is the difference between Soft page fault and Hard page fault?

One of the most common problems when dealing with Virtual memory – the Page Fault.  A page fault occurs when a program requests an address on a page that is not in the current set of memory resident pages.

Soft Page fault

A Soft Page fault occur when MMU (Memory Management Unit – its a Hardware) has not yet marked a page being loaded in memory.

MMU is responsible for translating Virtual memory to Physical memory address.

Hard Page fault

A hard page fault is when the memory manager finds that the block of memory its needs is not in RAM. That memory has been swapped out to disk, and your system slows down because it takes more time to get it from there.

The performance of applications will suffer when there is insufficient RAM and excessive hard page faults occur.

27. How are the GPOs applied? What is the GPO order of precedence?

GPOs precedence order is L S D OU as shown below

  1. Local Group Policy
  2. Site
  3. Domain
  4. Organizational unit (OU)

28. How will you restore an Active Directory Object? What kind of restore method you use?

Restart the Domain controller -> F8 -> Directory Service Restore Mode.

29. What is the difference between authoritative and non-authoritative restore?

If you Domain controller is crashed. We can restore them if you have Backup. During the restore option we have to choose either Authoritative or Non-Authoritative restore. You will get this option in Domain controller restart -> F8 -> Directory Services Restore Mode.

Non-Authoritative : Used most commonly in cases when a DC because of a hardware or software related reasons, this is the default directory services restore mode selection. In this mode, the operating system restores the domain controller’s contents from the backup. After this, the domain controller then through replication receives all directory changes that have been made since the backup from the other domain controllers in the network.

Authoritative : An authoritative restore is most commonly used in cases in which a change was made within the directory that must be reversed, such as deleting an organization unit by mistake. This process restores the DC from the backup and then replicates to and overwrites all other domain controllers in the network to match the restored DC. The especially valuable thing about this is that you can choose to only make certain objects within the directory authoritative.

For example, if you delete an OU by mistake you can choose to make it authoritative. This will replicate the deleted OU back to all of the other DC’s in the network and then use all of the other information from these other DC’s to update the newly restored server back up to date.

authoritative-and-non-authoritative-restore

http://www.windowsnetworking.com/kbase/WindowsTips/Windows2003/AdminTips/ActiveDirectory/Authoritativevs.Non-AuthoritativeRestorationofActiveDirectory.html

—————————–

Atlas Security

What will happen if only DNS in your environment goes down ?

Failing DNS can cause problems such as client authentication, application failure, Exchange failures with e-mail or GAL lookups, LDAP query failures, replication failures.

  1. Logins. Cached credentials would work, if the user had logged on before, but new domain logins would fail.
  2. Network shares. Your Kerberos ticket duration and enforcement are set by domain policy, but accessing network shares would begin to fail across your network.
  3. DNS. You and/or your service desk would begin to receive “no internet” calls. They’d still have connectivity, but they won’t be able to resolve things, inside or out. This could also have the effect of people calling you and/or your service desk to tell you your various servers are down.
  4. DHCP.  If DHCP is on this box, no one will be able to get a new IP address. (Ignore this point if you’re using something else for DHCP.) Your VPN uses AD credentials.
  5. Any other service that uses AD credentials (Network Access Control, websites with integrated security, etc.).

From http://serverfault.com/questions/580316/if-my-single-domain-controller-is-down-what-happens

—————————–

Microland interview questions

Round 1:

How do you perform Metadata cleanup ?

  • Through GUI, removal of entries from AD user and computers & AD sites and Services.
  • Metadata cleanup can also be performed through NTDSUTIL command

How do you verify once the Metadata cleanup and FSMO roles are seized?

  • We can use the following command to check what are the roles assigned to which Domain controller
  • netdom query fsmo

How can you recover an AD user account that was disabled for 30 days and deleted for the past 2 months ?

We can recover deleted AD object through AD recycle bin. This feature was introduced in Windows 2008. All deleted objects are in the AD database for 180 days before getting permanently removed. These deleted objects are called Tombstones.

Option 2 is to check Directory services restore Mode (Restart server -> press F8 -> Select Directory Services Restore Mode) but this option is only useful if you recently deleted an AD object and want to recover. Also there are options such as Authoritative or Non-Authoritative restore.

Have you ever done Cluster configuration in ESXi ?

How DRS works on ESXi environment ?

  • Dynamic Resource Scheduling (DRS) works by moving the VMs from a loaded ESXi to relatively free ESXi hosts.
  • This is done by Vcenter through vMotion.
  • By default, ESXi reserve 10% CPU and 10% RAM for DRS

What are the prerequisites needed for having DRS ?

  • Hosts in the DRS cluster should use a shared storage
  • Processor on the source host and destination host should be compatible (or same). Processor should come from same vendor. Clock speed and cache can vary. DRS cannot happen between ESXi that has Intel CPU on one ESXi and AMD on other ESXi.
  • Hosts must be part of vMotion network.
  • VMXF (VM configuration file) for ESXi host must reside in Virtual Machine File System (VMFS)
  • Atleast 1 Gigabit Ethernet is recommended. 10 Gigabit is recommended for large work loads.

Whenever a VM is created a hardware version is given to that VM? What is the hardware version ?

  • We should be aware of the VM Hardware version / VM version while trying to migrate to other VM environment (V2V)
  • If a virtual machine is created on a VMware product that supports a given virtual hardware version and is then migrated to a VMware product that does not support this level of virtual hardware, it does not power on.
  • Virtual machines created by VMware products and versions located higher up in the chart cannot be powered on by products lower on the chart.
  • A VMware product can power on a virtual machine with a virtual hardware version that is lower than what it supports, but functionality may be lost. Lost functionality results in menu items related to virtual machine operations being grayed out and unavailable.

vm-version

vm-version

vm-hardware-version-2

vm-hardware-version

virtual-machine-hardware-version

Note: The Option to upgrade VM hardware will only appear if your VM hardware version is low.

Steps to upgrade VM hardware version:

https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1010675

What is the difference between Forwarder and conditional Forwarder in DNS ?

Forwarder is usually used to forward queries that are resolvable outside our DNS. For example, we use forwarder to link to ISP (Internet Service Provider) ‘s DNS so that we can browse internet.

Conditional forwarder is used to forward only specific queries based on the domain. A conditional forwarder can be the DNS of other Business unit or other company which recently merged with our company.

What are the new features in DHCP in Windows server 2012 R2 ?

DNS registration enhancements

DNS PTR registration options –

Windows PowerShell for DHCP server – new PowerShell cmdlets

What is loop back processing of Group policy ?

Group Policy applies to the user or computer in a manner that depends on where both the user and the computer objects are located in Active Directory.

However, in some cases, users may need policy applied to them based on the location of the computer object alone. You can use the Group Policy loopback feature to apply Group Policy Objects (GPOs) that depend only on which computer the user logs on to.

  1. In the Group Policy Microsoft Management Console (MMC), click Computer Configuration.
  2. Locate Administrative Templates, click System, click Group Policy, and then enable the Loopback Policy option.

This policy directs the system to apply the set of GPOs for the computer to any user who logs on to a computer affected by this policy. This policy is intended for special-use computers where you must modify the user policy based on the computer that is being used. For example, computers in public areas, in laboratories, and in classrooms.

To use this policy, select one of the following policy modes from the Mode box.

  • Replace indicates that the user policies defined in the computer’s Group Policy objects replace the user policies normally applied to the user.
  • Merge indicates that the user policies defined in the computer’s Group Policy objects and the user policies normally applied to the user are combined. If the policy settings conflict, the user policies in the computer’s Group Policy objects take precedence over the user’s normal policies.

What is the Group Policy precedence in AD ?

Group policy precedence is L S D OU.

  • Local Group Policy
  • Site
  • Domain
  • Organization Unit (OU)

Round 2:

What is Phantom object in AD?

  • If the tombstone period of the object runs out AD removes it completely. However if there is a reference to the object still, the object remains in AD and becomes a phantom object.
  • Phantom objects are low-level database objects that Active Directory uses for internal management operations. Two common instances of phantom objects are:
    – Objects that have been deleted (tombstone passed but object still present).
    – A domain local group has a member user from another domain in the Active Directory forest.
  • Phantom objects are special kinds of internal database tracking objects that cannot be viewed through any LDAP interface.
  • Deleted objects that have exceeded the tombstone period will remain in AD, the object itself is deleted and a phantom object is created in its place. Phantom objects get automatically removed by the infrastructure master when the references are removed.

http://clintboessen.blogspot.in/2009/09/directory-services-tombstone-objects.html

What are the authentication protocols used in AD ?

Kerberos and NTLM.

Kerberos:

It is Microsoft’s version of Kerberos authentication protocol. Kerberos port 389. Kerberos is an authentication mechanism used to verify the identity of a user or host.

NTLM (NT Lan Manager):

If Kerberos is not available, AD will try to use NTLM.

What is the Kerberos version used in AD ?

Kerberos version 5 in Windows 7, 2008 R2.

If Kerberos is disabled in AD, what are the other authentication it will use to authenticate ?

AD also uses NTLM authentication mechanism. However, Kerberos is the primary authentication protocol. NT LAN Manager (NTLM). NTLM was introduced in Windows NT 4.0. It is Microsoft’s proprietary authentication protocol while Kerberos is open standard. For Backward compatibility reasons, Microsoft still support NTLM (version 2) in Windows 2012 R2.

Active Directory supports both Kerberos and NTLM. Windows will first try Kerberos and if all requirements are not met it will fallback to NTLM.

Example: Accessing file share by name like \server1\share would invoke Kerberos and should succeed given proper permision. But accessing same file share using IP address would invoke Kerberos first and fail (as there is no SPN for IP Address) and then fail over to NTLM.

https://technet.microsoft.com/en-us/library/hh831571(v=ws.11).aspx

http://serverfault.com/questions/31850/how-do-you-find-out-if-active-directory-is-using-kerberos-or-ntlm

http://serverfault.com/questions/682027/check-primary-authentication-protocol-for-active-directory-ntlm-or-kerberos

How do you monitor or know if replication is broken among Domain controllers ?

We can monitor replication through Microsoft AD Replication status tool and also using Repadmin command.

ad-replication-check-1

Use repadmin /? to see all the other commands.

To output this result into csv file:

repadmin /showrepl * /csv >showrepl.csv

ad-replication-check-2

Replication summary

repadmin /replsum

replication-summary

If you are facing Replication related issues, you can find the following errors in the Domain controller Event Viewer:

  • KCC
  • Long-running Inbound Replication
  • Conflict with Certificate Services
  • RPC Unavailable
  • Unknown User Name/Bad Password
  • Automatic Topology Generator Was Unable To Complete the Topology

Symptoms of Replication faults

  • Failure to extend the schema
  • Failure to DCPromo a new Domain Controller
  • Installation of Active Directory aware software
  • Any recent warnings or errors in the File Replication Service log in Event Viewer
  • Any recent NTDS Replication Errors in the Directory Service log in Event Viewer

https://technet.microsoft.com/en-us/library/cc961808.aspx

http://www.mcmcse.com/microsoft/guides/replmon.shtml

How to fix replication issues among Domain controllers ?

We can manually initiate Replicate among Domain controllers using AD Sites and Services. Right click the NTDS settings and select Replicate Now.

ad-manual-repliation

Through command line

repadmin /sync <directory_partition_DN> <destination_server_name><source_server_objectGuid>

Example: repadmin /sync dc=support,dc=microsoft,dc=com DC1 d2e3badd-e07a-11d2-b573-0000f87a546b

Example: repadmin /replicate server2.microsoft.com server1.microsoft.com dc=microsoft,dc=com

What are Lingering objects in AD ?

A lingering object is a deleted AD object that re-appears (“lingers”) on the restored domain controller (DC) in its local copy of Active Directory.

When restoring a backup file, Active Directory generally requires that the backup file be no more than 180 days old. (The limit is 60 days if the AD forest was originally created with Windows Server 2000.) If attempt to you restore an backup that is expired, you may encounter problems due to “lingering objects”.

When a DC deletes an object it replaces the object with a tombstone object. The tombstone object is a placeholder that represents the deleted object. When replication occurs, the tombstone object is transmitted to the other DCs, which causes them to delete the AD object as well.

Tombstone objects are kept for 180 days, after which they are garbage-collected and removed.

https://u-tools.com/help/LingeringObjects.asp

ad-objects

What will be the impact if KCC is disabled ?

KCC is Knowledge Consistency Checker, if disabled replication would not happen. We have to manually perform the replication.

The KCC is a process that maintains the intrasite and intersite replication topology in Active Directory forests. The KCC runs at regular intervals to adjust the replication topology for changes that occur in AD DS, such as adding new domain controllers and new sites.

What is VMware Network encapsulation ? How a physical NIC in the ESXi is shared with multiple VMs ?

In VMware, switches are used to establish a connection between the virtual network and the physical network. With ESX and ESXi, two different kinds of switches can be used: standard switches and distributed switches.

Standard Switches

  • A network standard switch, virtual switch, or vSwitch, is responsible for connecting virtual machines to a virtual network. A vSwitch works similar to a physical switch with some limitations.
  • Once the vSwitch has bridged the connection between the virtual network and the physical network, the virtual machines residing on the host server can begin transferring data between all the devices connected to the physical network.
  • Each virtual machine interfaces with the vSwitch via a port. vSwitches can consist of one or more port groups, which describe how the virtual switch should route traffic between the virtual network and the virtual machines connected to the specified ports.
  • Administrators can use port groups to configure traffic shaping and bandwidth limitations, NIC failover, and other settings.

Distributed Switches

Distributed virtual switches, or DvSwitches, simplify the network management of multiple ESX or ESXi hosts. DvSwitches provide the same features and functions as do vSwitches, but with one major difference: while a standard virtual switch can’t be assigned to more than one host server at a time, a DvSwitch can.

So, rather than create identical vSwitches for multiple hosts in a datacenter, you can instead create and associate a single DvSwitch with all the applicable ESX or ESXi servers.

vsphere-distributed-switch

  • Unlike vSwitches, which can be managed from the local host, DvSwitches must be created and controlled through vCenter Server.
  • DvSwitches also support port groups, called distributed port groups or dvport groups.
  • dvport groups provide the same basic functionality as do standard port groups, but offer additional features that the latter does not. For example, administrators can define not just outbound traffic shaping, but inbound traffic shaping as well, when working with dvPort groups.

https://www.pluralsight.com/blog/it-ops/virtual-networking-101-understanding-vmware-networking

What are the impact if you raise a Domain functional level from Windows 2003 to Windows 2008 R2?

One raised, both Domain and Forest functional level cannot be reversed.

What were the significant work you have done so far in Windows AD ?

DC rebuilds, Seizing FSMO roles, changing Domain controller DNS details into vCenter appliance, Working with teams and assigning Forwarder in DNS.

Have you worked on Certificates ?

Have you worked on load balancer / clusters ?

Have you worked on WSUS and SCCM ?

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Optiv

What is Empty Root Domain in AD ?

Empty Root Domain was an earlier Microsoft recommendation to create a main domain followed by a child / sub domain. All users and computers are created in the sub / child domain. Main Domain does not contain any of the usual user or computer objects. This was performed due to safety reasons. They say its to protect the AD Schema. However, nowadays this is not recommended by Microsoft. Microsoft want the Domain structure to be simple as possible unless you want it for any other business reason.

What is fine grained password policies in Group policy ?

  • You can use fine-grained password policies to specify multiple password policies within a single domain.
  • This feature was introduced in Windows server 2008
  • You can use fine-grained password policies to apply different restrictions for password and account lockout policies to different sets of users in a domain.
  • For example, you can apply stricter settings to privileged accounts and less strict settings to the accounts of other users. In other cases, you might want to apply a special password policy for accounts whose passwords are synchronized with other data sources.

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Cognizant Technology Solutions

Profile: Active Directory L3

What are the FSMO roles in AD. Give a brief intro.

Schema Master, Domain naming master, PDC Emulator, RID master and Infrastructure Master.

Tell me more about PDC Emulator.

PDC emulator is considered the important FSMO role. It is responsible for authentication, synchronizing time with clients.

If Infrastructure Master is down, would you be able to create user IDs ?

The purpose of Infrastructure master is only one thing: cross-domain object reference. So if Infrastructure Master is down, you can still create user objects in AD.

  • For example, if you add a user from one domain to a security group from a different domain, the Infrastructure Master makes sure this is done properly.
  • Infrastructure master does not have any functions to do in a single domain environment.
  • If the Domain controller with Infrastructure master role goes down in a single domain environment, there will be no impact at all. Where as, in a complex environment with multiple domains, it may impact creation and modification of groups and group authentication.

What is RID pool ?

  • Users, Computers and Groups are called Security Principals. Whenever a Security principal is created in AD it get unique ID called SID. SID contains Domain ID and Relative ID (RID).
  • Each domain controller is given a pool of RIDs by the RID master. The RID master (also known as the RID pool manager, RID manager, or RID operations master) is responsible for issuing a unique RID pool to each domain controller in its domain.
  • Newly promoted domain controllers must acquire a RID pool before they can advertise their availability to Active Directory clients or share the SYSVOL.
  • Existing domain controllers require additional RID allocations in order to continue creating security principals when their current RID pool becomes depleted.
  • By default, RID pools are obtained in increments of 500. A maximum of 1,073,741,824 (230) RIDs can be assigned to objects in AD.

If RID master goes down, what are the consequences ?

RID master is responsible for assigning new SID (Security Identifier) to objects (User and computers) in AD. If it goes down, we can create objects only till the RID pool has RIDs. We cannot create any more objects than that.

What are the ways to restore a deleted object in AD ?

You can use AD Recycle bin feature to restore a deleted object. By default, this feature is disabled in AD. You can also use LDP command to restore object.

Another way is to Directory service restore mode for AD. Restart the Server -> F8 -> Directory Services Restore Mode -> Choose Authoritative restore mode

AD Recycle bin feature is available in Windows 2008 server ?

No. AD Recycle bin feature is introduced in Windows 2008 R2 server only.

AD Recycle bin feature:

  • All Domain controllers within the AD forest must be running Windows server 2008 R2 or above.
  • Also the functional level of the AD forest must be Windows server 2008 R2 or above.

What to do if a set of new 100 users are unable to login ? While others are able to login. How will you troubleshoot ?

Occasionally, Windows might not read your user profile correctly, such as if your antivirus software is scanning your computer while you try to log on. Before you follow the methods here, try restarting your computer and logging on with your user account again to resolve the issue. If you restart your computer and it does not resolve this issue, use the following methods to resolve this issue.

Sometimes a single user might be not able to log on to domain. You can follow the checklist given below:

Make sure:

  • You can ping the domain controller from the user’s computer.
  • There is no white space in the User’s Home Profile in User’s Property > Check it using the DSA.MSC.
  • The user computer is configured with the correct DNS Server to find the domain controller > Check in TCP/IP property of the user’s computer.
  • The Computer Account in the domain for the user’s computer is not missing > Check using the DSA.MSC
  • The Computer Account in the domain is not disabled > Check using the DSA.MSC
  • The Time between the domain controller and the client computer is synchronized > Check using Net Time command.
  • The Domain Controller can be found > Check environment variables and check “LOGONSERVER” value or execute Nltest /DsGetDc:domain to re-locate the domain controller for the user.

What are the event logs associated if the above 100 users are not able to login ? Which log you would check and what is the log number / ID ?

Windows 2003 server: Event ID: 540

Windows 2008 server: Event ID: 4624

What to do if Windows XP clients are not taking the Group policies that are created in Windows 2012 R2 server ?

You need to install Group Policy Preference Client Side Extensions on Windows XP machines.

How to confirm if Group Policy Preference Client Side Extensions are installed in WinXP?

After you install above update in the computer will be able to process the new Group Policy Preference extensions. The below method helps you to confirm the update is properly installed.

1.   Locate the Gpprefcl.dll file in the below location. If the file is available, You are right, It has been installed properly.

2. In Registry editor, Find the below value that confirms the values are belongs GPP.

http://www.serverms.com/?p=408

What is DNS Stub zone and why we need it ?

Stub zone is to resolve names which are in a completely different domain. It is useful if we want to have name resolution with the other Business unit of our organization. Stub zone is dynamic. Whatever changes (addition or removal of DNS servers) in the DNS on the other end will be automatically reflected in our zone.

I have two Domain controllers, one is in India and other is in the US. The replication is not working and how do you fix it ?

Most common AD Replication errors in Event viewer:

  • Error -2146893022 (The target principle name is incorrect)
  • Error 1908 (Could not find the domain controller)
  • Error 8606 (Insufficient attributes were given to create an object)
  • Error 8453 (Replication access was denied)

Check the below link to address the common AD replication errors.

http://windowsitpro.com/active-directory/identifying-and-solving-active-directory-replication-problems

Identifying AD replication problems using:

  • AD Replication status tool
  • Repadmin command

 

Have you ever migrated OS from Windows 2008 to Windows 2012 server ?

Have you ever encountered KCC error ?

 

While installing Exchange server, Schema master needs to be up and running ?

Yes Schema Master is needed for Exchange server installation. The reason is, Exchange server will add new objects and attributes to the AD. These things needs to be added in the Schema Master. Since Schema master is responsible for all Object definitions in the AD. This process is called Schema Extension.

Also prior to the installation, the server needs to added in Domain and not in Work group.

 

I am having a problem with DC and it is not replicating. Have you ever heard of USN rollback ?

USN is Update Sequence Number. Whenever there is a change happened on an object, it is USN number gets incremented.  You can find that in AD sites and services -> Sites -> Servers -> NTDS Settings -> Properties -> Object.

usn

USN Rollback:

USN rollback occurs when the normal updates of the USNs are circumvented and a domain controller tries to use a USN that is lower than its latest update.

In Windows Server 2008 or Windows Server 2003 Service Pack 1 (SP1), USN rollback will be detected and replication will be stopped before divergence in the forest is created, in most cases.

USN rollback can be caused in many ways, when old virtual hard disk (VHD) files are used or physical-to-virtual conversion (P2V conversion) is performed without ensuring that the physical machine stays offline permanently after the conversion. Take the following precautions to ensure that USN rollback does not occur:

  • Do not take or use a snapshot of a domain controller virtual machine.
  • Do not copy the domain controller VHD file.
  • Do not export the virtual machine that is running a domain controller.
  • Do not restore a domain controller or attempt to roll back the contents of an Active Directory database by any other means than a supported backup solution, such as Windows Server Backup.

USN rollback may cause Replication errors.

In some cases, USN rollback may go undetected. In other cases, it may cause other replication errors. In these cases, it is necessary to identify the extent of the problem and take care of it in a timely manner. For information about how to remove lingering objects that may occur as a result of USN rollback

https://support.microsoft.com/en-in/help/875495/how-to-detect-and-recover-from-a-usn-rollback-in-windows-server-2003,-windows-server-2008,-and-windows-server-2008-r2

On a DC, SYSVOL folder is not shared. What do you do ?

You may encounter a situation in which SYSVOL and Netlogon shares are not shared on a domain controller. The following additional symptoms or conditions may also apply:

  • The SYSVOL folder is empty.
  • The affected domain controller was recently promoted.
  • The environment contains domain controllers running versions of Windows earlier than Windows Server 2012 R2.
  • DFS Replication is used to replicate the SYSVOL Share replicated folder.
  • An upstream domain controller’s DFS Replication service is in an error state.

What are the default shares on a DC ? How to check shares on a server ?

ADMIN$, C$, IPC$, Netlogon and SYSVOL are special administrative shares on Domain controllers.

domain-controller-share-2

SYSVOL is shared under %systemroot%\Sysvol\sysvol and NETLOGON is shared under %systemroot%\Sysvol\sysvol\domain\Scripts.

To check Shares on Windows 7 client, Computer Management (Right click My Computer -> Manage) -> System Tools -> Shared Folders -> Shares

shares-on-windows-7

To check shares on Windows 2008 R2 server, Server Manager -> Roles -> File Services -> Share and Storage Management

shares-on-windows-2008-r2

Command to check shares on remote server

net view remote-server-name

net view remote-server-name /all

domain-controller-share

domain-controller-share-2

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Atos

Profile: Wintel Admin, Total Time: 45 min

What are the difference between Windows 2003, 2008, 2012 R2 and 2016 servers ?

There are quite a lot in terms of features, hardware support etc.

server-comparison-03-to-16

I am experiencing Performance issue on Windows 2003 R2. As soon as I login it freezes and I am unable to check it ? How would you resolve the issue ?

How to trace what happened on the server that made the server freeze issue ? How to check what caused the issue in the past ?

How do you see what caused an issue with the computer in the past ? You can use Event viewer in general but it is tedious. Windows 7 or Windows 2008 R2 and above you can use Reliability Monitor. This is a GUI and OS built-in tool. Also very easy to use.

Click the day (cross mark) and the details of the critical events are shown below. You can also see solution to the problems. Link available at the bottom of the screen.

reliability-monitor

What is Trust ? What are the types of Trust in AD ?

Trust is created between two domains so that the user and computers in one domain can access resources residing in other domain.

ad-trust

Trust types:

Parent / Child trust: Trust between Parent and Child domain that have common DNS namespace.

This trust is established when a child domain is created in a domain tree.

Tree Root trust: Trust between root domains in same forest.

Shortcut trust: Trust between two domains in different domain trees within same forest. Improves user logon times

External trust:  Trust between AD domain and Windows NT4 domain

Realm trust: Trust between AD domain and a non-Windows kerberos realm

Forest trust: Forest trust is created between two forests.

Trust ways:

Trust can be one-way or two-ways

One-way trust:

One-way trust is divided into 2 types: incoming and outgoing trust

Incoming trust: Trust is created in the trusted domain. Users in trusted domain can access resources in both trusted and other domain. Users in other domain cannot access resources in trusted domain.

Outgoing trust: Users in the other domain able to access network resources in initiating domain. Users in initiating domain cannot access resources in other domain.

Two-way trust: Users in both domains can access resources at other side.

Trusts can be explicit and Implicit

Implicit: Trust that are automatically established when we create a child domain. This is a two-way trust.

Explicit: Manually created trusts are explicit.

What is DNS and it’s functions ?

How many types of DNS servers we can create ?

What are the DNS zones ?

What are Forward, Reverse, AD-Integrated DNS and Stub Zone ?

Why do you create Stub Zone ?

What is a Forwarder in DNS ?

What is a Global Catalog in AD ?

Have you worked on OS troubleshooting ? If my OS does not boot how would you troubleshoot it ?

What are the boot files in Windows 2003 and 2008 / 2008 R2 server ?

BootMGR, BCD are the boot files. These files resides in dedicated 100MB drive that is created during OS installation.

What is Amazon S3 ? What is the File system it has ?

S3 – Simple Storage Service. Amazon does not make details of S3’s design public, though it clearly manages data with an object storage architecture.

While Amazon EC2 uses Amazon Elastic File System.

What is Domain / AD replication ?

If one of the domain controller get crashed and you have a full back of the Domain controller. How would you go ahead and restore it to make sure it functions as intended ?

What happens in the background when you do an authoritative restore ?

How many types of DNS records do we have ?

What is the use of PTR record (Pointer record) ?

What is iLO ?

What is DRAC ?

What is the difference between iLO vs RDP ?

Remote Desktop connection is Windows OS specific. We can use it only when the remote OS is up and running.

iLO – Integrated Light Out is HP proprietary Server management technology

iDRAC – Dell Remote Access Control is Dell proprietary Server management technology

While iLO or iDRAC are hardware based. We can use it restart, shutdown the hardware irrespective of the OS installed on the hardware. iLO / iDRAC are useful when the OS installed on the hardware get crashed and we want to remotely reboot it.

 

On certain machines I find the SEP definitions are not updating. How do you resolve it and what are the logs you would check ?

  • Check whether the system has free space or not in the c:\
  • Check whether they are recently restarted or not. You can check it in the Task manager
  • Try to restart it one more time, if still the issue, check SEP is corrupted or not
  • Make sure the system has network connectivity
  • Try reinstalling SEP if any of these does not work.

How familiar are you with command prompt ? Are you able to work on server core server with just commands ?

What are the monitoring tools you have used ?

Power Admin monitoring tool

What is the role of VMtools in Virtual Machines ? (what is the use of VMtools ?)

VMTools is a set of drivers that helps / provides the following:

  • Helps improve mouse and cursor movement through console
  • Memory ballooning – VMtools gives back unused memory from VMs to ESXi host so that ESXi can provide those free RAM to needed hosts.
  • Quiesced snapshot of guest OS
  • Sync time in the guest OS with host
  • Improves sound, graphics, network performance

What is Memory Ballooning in Vmware ?

Memory Ballooning is the memory reclamation technique used by hypervisor to reclaim the memory back from the virtual machine. Ballooning will happen on the ESXi host which is running out of physical memory

What is paging ? It is physical or Virtual ?

Keeping the most frequently accessed in main memory and storing the rest in virtual memory.

It is also taking a chunk of HDD space as Virtual memory for swaping with RAM.

The file that is used in Windows for this is pagefile.sys

How many types of Hard drive you can create in Vmware (or) What are the storage types we can create in Vmware (Datastore) ?

SCSI and IDE Hard disk drives we can select. Also we can select the Mode as Independent which inturn gives two options such as Persistent and Nonpersistent (see 3rd screenshot).

vm-hdds-1

vm-hdds-2

vm-hdds-3

What is a LUN ?

A LUN can reference a disk, a portion of a disk, an entire storage array or part of a storage array.

In a Windows environment, there are five different types of LUNs that can be created:

  • Simple LUNs occupy a single physical disk or a portion of a single physical disk.
  • Spanned LUN. This type of LUN exist on multiple physical disks.
  • Striped LUN. Just like a spanned LUN, a striped LUN makes use of multiple disks. The difference is that striping writes data to each disk in the LUN at the same rate. The idea is to use multiple spindles to provide higher speed read and write access.
  • Mirrored LUN. A fault-tolerant set that uses two or more disks. Write operations are simultaneously performed on each disk in the mirror set.
  • Striping with parity. Striping with parity is very similar to a striped LUN. The difference is that parity data is written to each disk in the stripe set. This way, if a disk failure occurs, the parity information can be used to rebuild the lost disk. There are many different variations of striping with parity. Some can survive the failure of a single disk within a set, while others can survive multiple disk failures. Striping with parity delivers lower performance than a stripped LUN and provides significantly less storage space because of the overhead involved in writing and storing parity data.

What is iSCSI ?

iSCSI (Internet Small Computer System Interface)

iSCSI is a transport layer protocol that describes how Small Computer System Interface (SCSI) packets should be transported over a TCP/IP network. Because it uses standard Ethernet, iSCSI does not require expensive and sometimes complex switches and cards that are needed to run Fibre Channel (FC) networks.

In simple English, iSCSI is connecting your server to an external storage through Ethernet cable instead of Fiber optic cable.

http://searchstorage.techtarget.com/definition/iSCSI

iscsi

How do you configure iSCSI to configure on Windows 2008 R2 ?

In Windows Server 2008 R2, you can access the interface for Microsoft iSCSI Initiator by doing any of the following:

  • Click Start, click Control Panel, click Classic View, and then click iSCSI Initiator.
  • Click Start, click Administrative Tools, and then click iSCSI Initiator.

What is Fiber Channel ?

Fiber channel is a communication medium that uses Fiber Optic cable as a means of transmitting data. It uses LEDs as light source.

What is the difference in speed for Fiber optic over lan cable ?

  • LAN / Ethernet cable can transmit upto 10Gbps while Fiber optic can upto 100 tbps (tera bits per second).
  • Fiber optic is not vulnerable to Electro magnetic interference.
  • Fiber optic is difficult to intercept compared to Ethernet cable.

What is the name of the Fiber channel adapters that are used in Fiber optic cables ?

What is WWN and WWPN ?

  • WWN – World Wide Name is a unique identifiers on a Fiber Channel nettwork similar to the MAC address of an ethernet network
  • WWPN – World Wide Port Name is another name for the WWN assigned to the port on FC fabric
  • WWNN – World Wide Node Name is a WWN assigned to a node (an endpoint or device -on the FC Fabric )

What is VSS (Volume Shadow Service) ?

VSS in short is used for backup. Many backup tools today relay on VSS to effectively take backup.

VSS was introduced in Windows server 2003. It facilitates conversation between components to allow them to work better together. When all components supports VSS, you can use them to backup your application data without taking application offline.

Before VSS, Backup and restoring data was complex due to the following issue:

  • The data usually needs to be backed up while the applications that produce the data are still running. This means that some of the data files might be open or they might be in an inconsistent state.

VSS has 3 components:

  • Requestor—The application that requests the creation of a shadow copy.
  • Provider—The interface that provides the functionality to actually make the shadow copy.
  • Writer—Application-specific software that acts to ensure that application data is ready for shadow copy creation.

What is VSS writer ?

Application-specific software that acts to ensure that application data is ready for shadow copy creation.

Have you worked on clustering, load balancer ?

How do you make sure to allocate all the LUN for a particular VM ?

Answer: Raw Disk Mapping or Raw Device Mapping

A Raw Disk Mapping (RDM) can be used to present a LUN directly to a virtual machine from a SAN. Rather than creating a virtual disk (VMDK) on a LUN, which is generally shared with other VMs and virtual disks.

The main reason for using an RDM should be as follows:

  • To utilize native SAN tools and commands
  • If using Microsoft Cluster Services (MSCS), Failover Clusters or other clustering solution

Steps to RDM for local storage

https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1017530

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HCL

How to troubleshoot if GPO does not apply to say 50 servers ?

To check the Group policy on remote servers:

GPResult /S <Computer Name>

This instructs the command to get the GPResult from a remote computer.

You may also want to check the below page for common 10 mistakes in Group policy. Check part1 to part 3

http://www.windowsnetworking.com/articles-tutorials/windows-server-2008/Top-10-Reasons-Why-Group-Policy-Fails-to-Apply-Part1.html

Explain about your AD environment ?

How replication works in AD ?

Whenever an Object in AD is updated, its Update Sequence number (USN) gets incremented. Once Domain controller finds no more update to the object or AD database, it will wait for 5 minutes and replicate the data to other domain controllers.

This replication happens through Bridge head servers.

Knowledge Consistency Checker (KCC) is the process behind this. It runs on all Domain controllers and creates the replication topolgy. KCC runs at every 15 minute intervals by default even if you don’t make any change in the AD.

KCC automatically designates a single server, called the bridgehead server, in each site to perform site-to-site replication

At a time only 2 domain controllers replicate the data. The time between synchronizing with other domain controller is 30 seconds.

 

What are the types of replication ?

Intrasite Replication
Intersite Replication
Intersite Change Notification Replication
Urgent Replication
Reciprocal Replication
Immediate Replication
Manual Replication

Intrasite Replication

  • Replication within a site.
  • Intrasite Replication within a site notifies a partner DC 15 seconds after a change has occurred and all subsequent DC’s it communicates are delayed by 3 seconds.
  • All DC’s within a site are never more than 3 hops away from all other DC’s due to the KCC generating a bidirectional ring topology.

Intersite Replication

  • The shortest time span for intersite to occur is 15 minutes and the longest is once a week.
  • Replication happens can be set to happen on certain time of the day to save bandwidth

Intersite Change Notification Replication

Urgent Replication

Urgent notification is just that, it is not bound by the 15 second (Or 5 minutes) time delay of Intrasite Replication. Partner DC’s are immediately notified of changes, this only holds true for intrasite DC’s except if change site notification is enabled.
Reciprocal Replication

Replication is initiated on the basis of change rather than on a schedule

Sometimes connectivity isn’t always available, for example a Navy/Cruise ship or a dial up connection.
Immediate Replication

If an administrator resets a password for a user who has forgotten their password, the change is immediately replicated back to the PDCe.
Manual Replication

Manual replication is triggered by the admin. This can occur from either the repadmin command or from AD Sites and Services.

https://dirteam.com/paul/2011/04/06/active-directory-replication-types/

What is the event ID for KCC errors in event viewer ?

EVENT ID for KCC errors ar:

1311

1311 event indicates the KCC couldn’t connect up all the sites.

There is insufficient site connectivity information in Active Directory Sites and Services for the KCC to create a spanning tree replication topology. Or, one or more domain controllers with this directory partition are unable to replicate the directory partition information. This is probably due to inaccessible domain controllers.

1566

1566 event indicates the DC could not replicate from any server in the site identified in the event description.

All domain controllers in the following site that can replicate the directory partition over this transport are currently unavailable.

1865

When logged, the 1865 event contains secondary information about the failure to connect the sites and tells which sites are disconnected from the site where the KCC errors are occurring.

The Knowledge Consistency Checker (KCC) was unable to form a complete spanning tree network topology. As a result, the following list of sites cannot be reached from the local site.

How many DNS servers you can have in a Domain ?

Maximum number of DNS servers in an AD-integrated zone (without manually adding the details): 850 (Windows 2000), 1300 (Windows 2003).

For Windows Server 2003 DHCP servers, you can configure a list of up to 25 DNS servers for each client with this option.

What are the groups in AD and what are the differences between them ?

You are unable to login to HP iLO while the person in remote location is able to login. What would you do ?

iLO user name is case sensitive. Make sure to check case, spelling of username and passwords.

How to extend C:\ on Windows 2003 server ?

Use Dell extpart utility

In a Windows VM you want to extend the C:\ drive but it is greyed out. How do you fix it ?

Snapshot could be present on the VM

What is the boot order in Windows 2008 R2 server and what are the boot files ?

What is the boot order difference between Windows 2003 and 2008 server ?

Boot process for Windows 2003, XP, 2000, NT.

  1. BIOS performs POST (Power ON Self Test)
  2. BIOS loads MBR (Master Boot Record). MBR contains code that reads partition table.
  3. MBR loads boot sector
  4. Boot sector reads root directory of the system volume and loads NTLDR
  5. NTLDR reads BOOT.INI to determine boot drive
  6. NTLDR loads and executes NTDETECT.COM to perform BIOS hardware detection
  7. NTLDR then loads NTOSKRNL.EXE
  8. NTOSKRNL.EXE brings splash screen, initialize Kernel subsystem, starts system drivers
  9. SMSS.EXE – Starts Kernel mode and user mode partition. Starts Winlogin.exe
  10. WINLOGON.EXE – starts services controller. User can then login.

Note:
The SYSTEM volume is the partition from which the boot process starts, containing the MBR, boot sector, NTLDR, NTDETECT.COM & BOOT.INI

The BOOT volume is the partition which contains the Windows folder – this can be a logical partition

For more:

http://www.answers.com/Q/Windows_2003_booting_process

How do you troubleshoot a dump file ?

Windows XP has Dumpchk.exe

Microsoft Debug Diagnostics 2 and Nirsoft’s Bluescreen view are used for analyzing crash dump files.

If your system is unable to create crash dump what could be the issue ?

The system may not have adequate free space in C:\

ram-dump-file-size

How much space is needed for the system to create a full crash dump ?

Ideally the size of RAM + 1MB free space is recommended. However, modern systems have quite lot of RAM and the system usually cannot create a crash dump of more than 2GB. So a minimum of 2GB is needed.

What are the menus in Msconfig ?

Start -> Run -> msconfig

msconfig-1

msconfig-2

msconfig-3

msconfig-4

msconfig-5

When you try to boot a computer, you see the Windows logo however it does not proceed further. It just restarts repeatedly. How do you resolve this ?

This could be due to Anti-Virus and that is not allowing the computer to boot.

Disabling an Anti-virus service in Msconfig while in safe mode.

What is a parity. What is stored in parity in RAID 5 ?

Parity uses XOR operation.

The parity is generated by grouping together the bits (0 an 1s) to be written, then flipping the bits for the parity data by making the 1 bits 0s and the 0 bits 1s. This is an XOR operation.

A bit (0 or 1) is then added to each group of data bits so that it will have either an odd or even number of 1s. When reading back the parity, if the parity that was generated was odd, then any group of bits that arrives with an even number of 1s for that data must be in error. The data can then be regenerated using the parity information from the other disks.

RAID 5 uses distributed parity. This means parity information for each write is distributed in striped form across all disks in the set.

How do you increase a server’s HDD capacity from 300GB (100GB x 3) to 600GB. These HDDs are configured in RAID 0.

  • Remove one drive from a server at time and replace it with a 200GB drive.
  • Once you replace a drive, leave it for some time so that the RAID will recreated with the new drive. This rebuild is accomplished by the RAID controller.
  • Similarly do for other 2 drives.

How page file works ?

Page file works by using a portion of the HDD as temporary memory. This is useful when you don’t have adequate free space in RAM.

However, CPU cannot process application which are in Page file. It will swap the contents between Page file and RAM while processing.

What is the difference between Swap and Page ?

Swap file swaps an entire program between page file. This is useful for programs that are small in size

Page splits a program to 64KB in size and swaps with HDD and page file while processing. This is useful for programs that are very large in size.

What are the types of queries in DNS ?

Recursive and Iterative queries

Recursive Query

A recursive query is a kind of query, in which the DNS server, who received your query will do all the job of fetching the answer, and giving it back to you. During this process, the DNS server might also query other DNS server’s in the internet on your behalf, for the answer.

Iterative query

In an iterative query, the name server, will not go and fetch the complete answer for your query, but will give back a referral to other DNS server’s, which might have the answer.

What are the FSMO roles ?

Schema Master, Domain naming master – both Forest wide roles

RID master, Infrastructure master and PDC emulator – all three Domain wide roles

Global catalog is not included in FSMO (Flexible Single Master Operations) why ?

Global catalog is a multi-master and not Single master that is the reason.

What is Knowledge Consistency Checker – KCC ?

KCC is a built-in process in Domain controllers that performs the replication, responsible for establishing replication topology.

KCC is responsible for setting up replication between Bridge head servers. KCC selects the Bridge head servers.

How many servers you can have with Global Catalog role in a domain ?

The global catalog is the master index of objects within an Active Directory forest. The global catalog serves as a quick search tool to locate objects within a forest. Every domain must have at least one global catalog server. The first domain controller (DC) installed into a domain automatically serves as that domain’s global catalog server by default. As the size of your forest grows, there may become a need to configure additional global catalog servers throughout the forest (i.e., in each domain).

when fewer global catalog servers are deployed in a forest, there will be less replication traffic, but it will cause more query traffic. Conversely, deploying more global catalog servers in a forest will cause more replication traffic, but reduce query traffic.

What are the RAID levels ? What is RAID 0 ?

RAID 0 is striping. You need two or more HDDs for RAID 0. RAID 0 is not data safe. So if 1 HDD fails, all your data get lost.

What is the use of RAID 0 vs a single HDD or no-RAID ?

RAID 0 is striping. You need two or more HDDs for RAID 0. RAID 0 is not data safe. So if 1 HDD fails, all your data get lost. However, there is a performance benefit of using RAID 0 instead of no-RAID.

Data is simultaneously written and read on multiple HDDs instead of single HDDs. On multiple HDDs, you have multiple spindles that read the disks makes read and write faster than no-RAID.

What is the benefit of RAID 0, 1 and 5 ?

RAID 0 – Striping – Read and Write Performance compared to RAID 1 and no-RAID

RAID 1- Mirroring – Data is safe if one HDD crashes. Performance is slow compared to RAID 1 since data needs to be written on both HDDs.

RAID 5- Stripe with Parity – Faster and data safe.

What is the use of RAID ?

Redundant Array of Inexpensive Disks.

RAID is a technology that is used to increase the performance and / or reliability of data storage.

——————————

Synechron Feb 20 2017

 

What kind of services you are looped in for AWS?

AWS EC2, S3, IAM etc

What are the new features in Windows 2012, 2012 R2 and 2016 server?  

Features in Windows 2012 server:

Resilient File System (ReFS)

The Resilient File System (ReFS) was designed as an evolution of the New Technology File System (NTFS) with a focus on availability and integrity. ReFS writes to different locations on disk in an atomic fashion, which improves data resiliency in the event of a power failure during a write, and includes the new “integrity streams” feature that uses checksums and real-time allocations to protect the sequencing and access of both system and user data.

Problems identified by Windows Server 2012 on volumes protected with these features can be automatically repaired without bringing the disk or volume offline in most cases—and in many cases without any administrative intervention either. ReFS is also built to scale further than NTFS as well, which is an important point in the age of big data and private cloud operations.

New server manager

No Enterprise edition. Only Standard or Datacenter edition

Hyper-V Replication

The Hyper-V Replica feature allows you to replicate a virtual machine from one location to another with Hyper-V and a network connection—and without any shared storage required.

DirectAccess

DirectAccess allows VPN-like secure tunneling from any endpoint back to the corporate network without the overhead and performance hit of a true VPN. There is also no management agent on the client.

Out-of-the-Box IP Address Management

In the box with Windows Server 2012, youll find a complete IPAM suite. This is something many medium-sized businesses simply don’t have access to. With the IPAM suite, you can allocate, group, issue, lease and renew IP addresses in an organized fashion, as well as integrate with the in-box DHCP and DNS servers to discover and manage devices already on your network. If youve not played with IPAM services from Nortel and others, this is a very interesting and worthwhile inclusion to the product—and, as it’s free with the OS license

Features in Windows 2012 R2 server:

Tiered storage spaces

Allows a mix of SSD and HDD in a single space and the storage spaces engine automatically moves the hot blocks to the SSD from the HDD

Work folders

Enable users to have access to all their data by replicating all user data to corporate file servers then back out to other devices. Data is also encrypted and if a user device is un-enrolled from management the data corporate data is removed.

New PowerShell Desired State Configuration extension as part of PowerShell 4

What is NIC Teaming ?

NIC Teaming is the process of combining multiple network cards together for performance and redundancy reasons. Microsoft refers to this as NIC teaming, however other vendors may refer to this as bonding, balancing or aggregation. The process is the same regardless which solution is used or what it is called.

Also known as Load balancing and failover (LBFO), allows multiple network adapters on a computer to be laced into a team for

  • Bandwidth aggregation
  • Traffic failover to prevent connectivity loss in the event of a network component failure

——————————

Danske IT (Danske Bank)

 

What is the monitoring tool you are using ?

What are the critical issues you have faced in your current organization ? How did you troubleshoot and resolved it ?

Which vendor brand servers you have in your environment ?

If you face issue with remote server how do you troubleshoot it ?

We have Dell and HP servers, they have iDRAC and iLO. We can login to these through Web browser and check the issue on these servers.

What are the FSMO roles ?

Schema Master, Domain Naming Master, PDC Emulator, Infrastructure Master and RID Master.

First two are Forest wide. Other three are Domain wide.

Which is one is the critical FSMO role ?

PDC Emulator

How do you recover an deleted object in AD ?

  1. Through AD recycle bin (if it is Windows 2008 R2 server and if the feature is enabled)
  2. Through Directory services restore mode (Restart the server -> F8). There are two options here: One is Authoritative and other is  Non-Authoritative restore. Here we need to choose Authoritative restore option.

What is RAID ?

Redundant Array of Inexpensive or Independent Disks is the acronym for RAID.

It allows us to group multiple Hard disk drives to store data in striping, mirroring or a combination of these with parity for data security. There are many types of RAID.

RAID 0, 1, 5, 6, 10, 0+1 are some of the examples

What is RAID 5 ?

RAID 5 is known as striping with parity. A minimum of 3 HDDs are required. One HDD will be used as parity.

What are your daily tasks in VMware ?

What are the reasons when one of a VM does not power ON while you trying to power ON it ?

Examples:

  • .vmx file of the VM get corrupted
  • ESXi memory has been completely utilized

https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1006232

What is vMotion and svMotion ?

vMotion: VM movement between hosts

Storage vMotion: VM movement between datastores.

What are the prerequisites for vMotion and svMotion ?

vMotion prerequisites:

A virtual machine and its host must meet resource and configuration requirements for the virtual machine files and disks to be migrated with vMotion in the absence of shared storage.

vMotion in an environment without shared storage is subject to the following requirements and limitations:

  • The hosts must be licensed for vMotion.
  • The hosts must be running ESXi 5.1 or later.
  • The hosts must meet the networking requirement for vMotion.
  • The virtual machines must be properly configured for vMotion.
  • Virtual machine disks must be in persistent mode or be raw device mappings (RDMs).
  • The destination host must have access to the destination storage.
  • When you move a virtual machine with RDMs and do not convert those RDMs to VMDKs, the destination host must have access to the RDM LUNs.
  • Consider the limits for simultaneous migrations when you perform a vMotion migration without shared storage. This type of vMotion counts against the limits for both vMotion and Storage vMotion, so it consumes both a network resource and 16 datastore resources. See Limits on Simultaneous Migrations in the vSphere Web Client.

Do you need separate VLAN required for vMotion ? Which is it ?

vMotion requires separate VLAN. The reasons are:

  • vMotion traffic is quite huge. There will be huge burst of traffic when ESXi goes down or get loaded.
  • vMotion traffic is not encrypted. The traffic in vMotion is nothing but a VM’s RAM contents.

You can check this by

vCenter -> Hosts and Clusters -> Click Host -> Configuration -> Networking

vmotion-vlan

What are the difference between VMware version 5.1 and 5.5 ?

Web access was introduced in vSphere 4.0

https://pubs.vmware.com/vsphere-4-esx-vcenter/index.jsp?topic=/com.vmware.vsphere.dcadmin.doc_41/vsp_dc_admin_guide/vsp_interfaces/c_vi_web_access.html

difference-between-vsphere-5-05-1-5-5-6-0

http://www.vmwarearena.com/vsphere-6-0-difference-between-vsphere-5-0-5-1-5-5-and-vsphere-6-0/

What is the patching tool you are using ?

Altiris

Do you do automation using PowerShell and PowerCLI scripts ?

——————————

Danske 2nd round

What is the background working of Kerberos authentication ?

  • Kerberos protocol was created by MIT (Massachusetts Institute of Technology).
  • Password is encrypted before sending over the network.
  • Client sends encrypted password to KDC with date and time.
  • Domain controller contains Key Distribution Center (KDC) which provides key tokens to clients.

What is a VLAN ?

How a VM environment is connected to storage ?

  • Serial Attached SCSI (SAS)
  • Fibre Channel
  • Fibre Channel over Ethernet (FcoE), or iSCSI.

In IP / 24 subnet, how many hosts you can have in that range ?

/24 is a network mask of 255.255.255.0

There are 256 total hosts IP in /24 range in all Class A, B and C IP range. Out of which 2 IPs are not usable So 254 usable IPs.

 

——————————

Capita

Is it possible to run Windows server 2012 systems in a cluster with earlier versions of Windows server ?

Name the shared folder that exists on all domain controllers and is used to store Group Policy objects, login scripts and other files that are replicated domain wide ?

Name the command line tool used for monitoring Active Directory provides functionality that includes performing connectivity and replication tests ?

Replmon – Windows 2003 and older OS

Repadmin – Windows 2008 and newer

Define the procedure used only when you have experienced a catastrophic failure of a domain controller that holds a FSMO role and you need to recover that role ?

Seize FSMO role through ntdsutil command and assign it to other domain controller.

Additionally create a new domain controller and add it as an additional domain controller.

In Windows server 2008, you must back up ______ rather than only backing up the system state data.

What is the purpose of sysvol ?

SYSVOL stores and replicates Group policies, log on and log off scripts between domain controllers.

What is the difference between domain local group and a global group ?

What is the difference between scope and super scope ?

Scope and Superscope terms are used in Windows DHCP

Scope

Scope is a grouping of IP addresses for computers that use DHCP service.

Superscope

A Superscope can have multiple scopes (multiple network segments).

Which DNS server contains no zones and hosts no domains ?

What locator records within DNS allow clients to locate an Active Directory domain controller or global catalog ?

How would you backup AD database in a Windows 2008 server ?

https://technet.microsoft.com/en-us/library/cc771290(v=ws.10).aspx

https://www.pluralsight.com/blog/tutorials/backup-and-restore-active-directory-on-windows-server-2008

What happens to the VMs if a standalone host is taken to maintenance mode ?

What is the major difference between Windows server 2008 and Windows server 2012 in terms of AD promotion ?

Why can’t you restore a DC that was backup 4 months ago ?

VMKernel port group can be used for ?

List some major differences ESXi 5.1 and 5.5 free versions

vMotion is not working. What are the possible reasons ?

What is a vCenter agent ?

Whenever an ESXi host is added into vCenter,

What are the files that make a Virtual machine ?

.vmdk

-flat.vmdk

.vmem

.vswp

.vmx

.nvram

—————

snapshot

.vmsd

.vmsn

-delta.vmdk

 

How to rename a Domain controller and what are the implications if you rename it ?

Domain controller rename is possible but you cannot simply goto My computer -> Properties and rename it like on a normal desktop.

You need to use netdom command for DC renaming.

Incorrect renaming could make clients unable to login, SYSVOL folder replication failure (Group policies, Logon and logoff scripts) etc.

What is IMA (Independent Management Architecture) ?

What is the grace period once the license expires within Citrix Farm ?

Explain DAG ?

Difference between the architecture of Exchange 2003 and 2010 ?

Explain different roles of Exchange 2010

Explain EDGE sync with regards to Exchange 2010

 

——————————

Other Interview questions and answers

  1. What is the partition you want to create if you want to have a drive for 2TB or more ? answer is GPT (GUID Partition Table)

GPT partition

2. Is it possible to “Hot Add” CPU and Memory for a VM ? Yes. It is. You can find this option in a VM -> Edit settings -> Options -> Advanced -> Memory / CPU Hotplug. Note: The option to Disable or Enabling this will be available only if the VM is in Powered off state.

CPU Memory hotplug

3. What is a Quoram ?

Quoram is a storage medium in which “Cluster configuration database” is stored. Quoram provides information to the cluster about active servers at any point of time. “Quoram is a DB related one”

In networking, clustering is the use of multiple servers (computers) to form what appears to users as a single highly available system. A Web page request is sent to a “manager” server, which then determines which of several other servers to forward the request for handling. Cluster computing is used to load-balance the traffic on high-traffic Web sites. Load balancing involves dividing the work up among multiple servers so that users get served faster.

Although clusters comprise multiple servers, users or other computers see any given cluster as a single virtual server. The physical servers themselves are called cluster nodes. The quorum tells the cluster which node should be active at any given time, and intervenes if communications fail between cluster nodes by determining which set of nodes gets to run the application at hand. The set of nodes with the quorum keeps running the application, while the other set of nodes is taken out of service.

http://whatis.techtarget.com/definition/cluster-quorum-disk

Windows 2008 cluster supports four quorum models.
1 Node Majority
2 Node and Disk Majority
3 Node and File Share Majority
4 No Majority (disk only)
Node Majority: Node majority option is recommended for cluster with odd number of nodes.This configuration can handle a loss of half of the number of cluster nodes rounded off downwards. For example , a five node cluster can handle failure of two nodes. In this scenario three of the nodes (N1,N2,N3) can communicate each other but other two(N4 and N5) are not able to communicate. The group constituted by three node have the quorum (majority) and cluster will remain active and cluster service will be stopped on the other two nodes (N4 and N5). The resource group (sql server instance) hosted on that two nodes goes offline and come online on one of the three nodes based on possible owner settings.
Node and Disk Majority: This option is recommended for cluster with even number of nodes.In this configuration every node gets one vote and witness disk (quorum disk) gets one vote which makes total votes a odd number. The witness disk is a small ( approx 1 GB ) clustered disk.This disk is highly available and can failover between nodes. It is considered as part of the cluster core resource group.In a four node cluster, if there is a partition between two subsets of nodes, one of the subset will have witness disk and that subset will have quorum and cluster will remain online. This means that the cluster can lose any two voters,whether they are two nodes or one node and the witness disk.
Node and File Share Majority: This configuration is similar to the the Node and Disk Majority, but in this case the witness disk is replaced with a file share which is also known as File Share Witness Resource (FSW). This quorum configuration usually used in multi-site clusters (nodes are in different physical location) or where there is no common storage. The File Share Witness resource is a file share in any server in the same active directory which all the cluster nodes have access to. One of the node in the cluster will place a lock on the the file share to consider that node as owner of the file share.When this node goes offline or lost the connectivity another node grabs the lock and own the file share.On a standalone sever, the file share is not highly available , however the file share can also put on a clustered file share on an independent cluster,making the FSW clustered and giving it the ability to fail over between node. It is important that, this file share should not put in a node of the same cluster, because losing that node would cause for loosing two votes. A FSW does not store cluster configuration data like witness disk. It contain information about which version of the cluster configuration database is most recent.
No Majority (Disk only) : This configuration was available in windows server 2003 and has been maintained for compatibility reason and it is highly recommended not to use this configuration. In this configuration,only witness disk has a vote and there are no other voters in the cluster. That means if all nodes are online and able to communicate , but when witness disk failed or corrupted, the entire cluster will go offline.This is considered as single point of failure.

————————–

Some of the info collected from below sites:

https://support.dnsimple.com/articles/cname-record/

AD partitions:

Directory Partitions

and other sites. Please comment if I failed to mentioned you.

DNS records:

http://dns-record-viewer.online-domain-tools.com/

PDC emulator importance:

https://citruspk.wordpress.com/2012/12/26/pdc-emulator-most-important-fsmo-role/

http://searchvmware.techtarget.com/definition/affinity-rules

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