Sunday, March 8, 2015

Wintel Interview Questions and Answers


1) Differences b/w Conditional Forwarding and Stub Zones.
Ans:- Both do the same thing like forwarding the requests to appropriate name servers who are authoritative for the domains in the queries. However, there is difference in both, Stub Zone are Dynamic and Conditional forwarder are static.
Conditional Forwarding –   Where you want DNS clients in separate networks to resolve each others’ names without having to query DNS servers on the Internet, such as in the case of a company merger, you should configure the DNS servers in each network to forward queries for names in the other network. DNS servers in one network will forward names for clients in the other network to a specific DNS server that will build up a large cache of information about the other network. When forwarding in this way, you create a direct point of contact between two networks’ DNS servers, reducing the need for recursion.
Stub Zone- Stub-Zones are dynamic -A stub zone is like a secondary zone in that it obtains its resource records from other name servers (one or more master name servers). A stub zone is also read-only like a secondary zone, so administrators can’t manually add, remove, or modify resource records on it. But the differences end here, as stub zones are quite different from secondary zones in a couple of significant ways.First, while secondary zones contain copies of all the resource records in the corresponding zone on the master name server, stub zones contain only three kinds of resource records:
  • A copy of the SOA record for the zone.
  • Copies of NS records for all name servers authoritative for the zone.
  • Copies of A records for all name servers authoritative for the zone.
2) How AD Replication Works ?
3) How DNS is important in AD replication?
Ans:- Once DC gets its replication Partner Hostname then it queries DNS for IP Address. Also, _MSDCS zone is required for Domain Controller Locator that enables the client to locate the DC.
For complete details
4) Ports Required for Domain Controllers to communicate.
5) What is GPT and GPC?
Ans:- A GPO (Group Policy Object) is a collection of Group Policy settings, it consists of GPC and GPT.
GPC (Group Policy Container) contains the information of property of GPO like Security Filtering, GPO Status, GPO GUID etc.
GPT (Group Policy Template) contains the data of GPO in Sysvol folder that can be checked after the configuration of the GPO that what settings have been configured to the client.
6) What is new in Microsoft Clustering 2008?
7)  What is Majority Node Set?
Ans:- A majority node set is a single quorum resource, from a server cluster perspective; however, the data is actually stored on multiple disks across the cluster. Each cluster node stores the configuration on a local disk it can have access to when it starts up. By default, the location is pointed to %systemroot%\cluster\ResourceGUID
If the configuration of the cluster changes, that change is replicated across the different disks
8) What is NLB?
Ans:- NLB (Network Load Balance)  is a Microsoft implementation of clustering and load balancing that is intended to provide high availability and high reliability, as well as high scalability.
9) Difference Between Unicast and Multicast
Ans:-

Unicast

Unicast is a one-to one connection between the client and the server. Unicast uses IP delivery methods such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP), which are session-based protocols. When a Windows Media Player client connects using unicast to a Windows Media server, that client has a direct relationship to the server. Each unicast client that connects to the server takes up additional bandwidth. For example, if you have 10 clients all playing 100-kilobits per second (Kbps) streams, those clients as a group are taking up 1,000 Kbps. If you have only one client playing the 100 Kbps stream, only 100 Kbps is being used.

Multicast

Multicast is a true broadcast. The multicast source relies on multicast-enabled routers to forward the packets to all client subnets that have clients listening. There is no direct relationship between the clients and Windows Media server. The Windows Media server generates an .nsc (NetShow channel) file when the multicast station is first created. Typically, the .nsc file is delivered to the client from a Web server. This file contains information that the Windows Media Player needs to listen for the multicast. This is similar to tuning into a station on a radio. Each client that listens to the multicast adds no additional overhead on the server. In fact, the server sends out only one stream per multicast station. The same load is experienced on the server whether only one client or 1,000 clients are listening
10) What is new in Windows 2008 AD?
Ans:-
Read-Only Domain Controllers
Fine-Grained Password Policies
Restartable Active Directory Service
Backup and Recovery
SYSVOL Replication with DFS-R
Auditing Improvements
UI Improvements
11) How to configure RODC to replicate password of users?
Ans:- You can add users in the PASSWORD REPLICATION POLICY tab of RODC computer properties
12) What is the issue we face while recovering AD from VMware snapshot?
13) Difference between Authoritative and Non-authoritative restore in AD?
14) What is new in Authoritative restoration in windows 2008?
15)  What is new in Windows Cluster 2008?
16) What is Strict Replication?
Ans:-
Strict Replication is a mechanism developed by Microsoft developers for Active Directory Replication. If a domain controller has the Strict Replication enabled then that domain controller will not get “Lingering Objects” from a domain controller which was isolated for more than the TombStone Life Time. TSL is 180 days by default on a Forest created with Windows Server 2003 SP1. A domain controller shouldn’t be outof sync for more than this period. Lingering Objects may appear on other domain controllers if replication happens with the outdated domain controllers. These domain controllers will not replicate with the outdated domain controllers if you have set the below mentioned registry key.You must set the following registry setting on all the domain controllers to enable the Strict Replication:
  •   KEY Name: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters
  •   Registry Entry: Strict Replication Consistency
  •   Value: 1 (enabled), 0 (disabled)
  •   Type: REG_DWORD
17) What is Super Scope in DHCP?
Ans:-
A superscope is an administrative feature of Dynamic Host Configuration Protocol (DHCP) servers running Windows Server 2008 that you can create and manage by using the DHCP Microsoft Management Console (MMC) snap-in. By using a superscope, you can group multiple scopes as a single administrative entity. With this feature, a DHCP server can:
  • Support DHCP clients on a single physical network segment (such as a single Ethernet LAN segment) where multiple logical IP networks are used. When more than one logical IP network is used on each physical subnet or network, such configurations are often called multinets.
  • Support remote DHCP clients located on the far side of DHCP and BOOTP relay agents (where the network on the far side of the relay agent uses multinets).
In multinet configurations, you can use DHCP superscopes to group and activate individual scope ranges of IP addresses used on your network. In this way, the DHCP server can activate and provide leases from more than one scope to clients on a single physical network.
Superscopes can resolve specific types of DHCP deployment issues for multinets, including situations in which:
  • The available address pool for a currently active scope is nearly depleted, and more computers need to be added to the network. The original scope includes the full addressable range for a single IP network of a specified address class. You need to use another range of IP addresses to extend the address space for the same physical network segment.
  • Clients must be migrated over time to a new scope (such as to renumber the current IP network from an address range used in an existing active scope to a new scope that contains another range of IP addresses).
  • You want to use two DHCP servers on the same physical network segment to manage separate logical IP networks.
18) What is the requirement to configure Full memory Dump in windows?
Ans:-
To generate a complete memory dump file:
  1. Click Start > right-click Computer and select Properties in the menu.
  2. Click Advanced > Settings > Startup and Recovery > Settings > Write debugging information > Complete memory dump.
  3. Click OK twice.
19) Which DNS record is required for Replication?
Ans:- Host A records of replication partners (Domain Controllers), Srv Records to find out the Domain Controllers  GUID in _msdcs zone (DC Locator)
20) Tools to analyze Memory Dump?
Ans:-
Windows Debugger (WinDbg.exe) tool
Dumpchk,exe
21) Tools to troubleshoot Group Policy issues?
Ans:- You can use AD inbuilt features to troubleshoot group policy issue like RSOP.msc or can run RSOP by selecting users in Active Directory users and computers, gpresult -v, gpt.ini in sysvol under Group Policy GUID folder can be checked to find out the GPO settings configured
22) What AD parameters can be added to enable the Monitoring for AD?
23) How to troubleshoot AD replication issues?
Ans:- It can be troubleshooted by repmon command that generates the error result in eventvwr. DNS can be checked between two destination. Network/Firewall issue
24) Booting sequence in windows 2008?
Here’s the brief description of Windows Server 2008 Boot process.
  1. System is powered on
  2. The CMOS loads the BIOS and then runs POST
  3. Looks for the MBR on the bootable device
  4. Through the MBR the boot sector is located and the BOOTMGR is loaded
  5. BOOTMGR looks for active partition
  6. BOOTMGR reads the BCD file from the \boot directory on the active partition
  7. The BCD (boot configuration database) contains various configuration parameters( this information was previously stored in the boot.ini)
  8. BOOTMGR transfer control to the Windows Loader (winload.exe) or winresume.exe in case the system was hibernated.
  9. Winloader loads drivers that are set to start at boot and then transfers the control to the windows kernel.

25) How to edit Schema in AD?
Ans:- Firstly, schmmgmt.dll has to be register. Then ADSIEdit tool can be used to edit schema.
26) Difference between Windows 2003 & Windows 2008 boot process
Ans:-
Windows 2003 Boot Process:
1.POST
2.The MBR reads the boot sector which is the first sector of the active partition.
3.Ntldr looks path of os from boot.ini
4.Ntldr to run ntdedetect.com to get information about installed hardware.
5.Ntldr reads the registry files then select a hardware profile, control set and loads device
drivers.
6.After that Ntoskrnl.exe takes over and starts winlogon.exe which starts lsass.exe
Windows Server 2008 Boot process.
  1. System is powered on
  2. The CMOS loads the BIOS and then runs POST
  3. Looks for the MBR on the bootable device
  4. Through the MBR the boot sector is located and the BOOTMGR is loaded
  5. BOOTMGR looks for active partition
  6. BOOTMGR reads the BCD file from the \boot directory on the active partition
  7. The BCD (boot configuration database) contains various configuration parameters( this information was previously stored in the boot.ini)
  8. BOOTMGR transfer control to the Windows Loader (winload.exe) or winresume.exe in case the system was hibernated.
  9. Winloader loads drivers that are set to start at boot and then transfers the control to the windows kernel.

27) Name of utilities that is being used to check multipathing
Ans:- FCInfo utility or Storage Explorer (windows 2008) can be used to check the same.
28) How to create Host A record remotely?
Ans:-  dnscmd command can be used for creating a Resource Record on DNS server. Below is the command:
dnscmd [<ServerName>] /recordadd <ZoneName> <NodeName> <RRType> <RRData>
29) What is glue record?
Ans:-
Name servers in delegations are identified by name, rather than by IP address. This means that a resolving name server must issue another DNS request to find out the IP address of the server to which it has been referred. If the name given in the delegation is a subdomain of the domain for which the delegation is being provided, there is a circular dependency. In this case the name server providing the delegation must also provide one or more IP addresses for the authoritative name server mentioned in the delegation. This information is called glue. The delegating name server provides this glue in the form of records in the additional section of the DNS response, and provides the delegation in the answer section of the response.
For example, if the authoritative name server for example.org is ns1.example.org, a computer trying to resolve www.example.org first resolves ns1.example.org. Since ns1 is contained in example.org, this requires resolving example.org first, which presents a circular dependency. To break the dependency, the name server for the top level domain org includes glue along with the delegation for example.org. The glue records are address records that provide IP addresses for ns1.example.org. The resolver uses one or more of these IP addresses to query one of the domain’s authoritative servers, which allows it to complete the DNS query.
30) What is Loopback Group Policy?
Ans:- 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.
31) Difference between Windows 2003 and Windows 2008
32) TCP/UDP ports used in Windows?
33) Types of RAID

What is RAID configuration in Windows

RAID Configuration

Learn about Intel RAID configuration. It includes all the RAID levels with diagram, very useful for to clear doubts for layman.
RAID Level 0 requires a minimum of 2 drives to implement
Characteristic & Advantages
RAID 0 implements a striped disk array, the data is broken down into blocks and each block is written to a separate disk drive.
I/O performance is greatly improved by spreading the I/O load across many channels and drives.
Best performance is achieved when data is striped across multiple controllers with only one drive per controller.
No parity calculation overhead is involved.Very simple design & Easy to implement.
Not a “True” RAID because it is NOT fault-tolerant
The failure of just one drive will result in all data in an array being lost &Should never be used in mission critical environments

Disadvantages
Not a “True” RAID because it is NOT fault-tolerant.
The failure of just one drive will result in all data in an array being lost
Should never be used in mission critical environments

For Highest performance, the controller must be able to perform two concurrent separate
Reads per mirrored pair or two duplicate Writes per mirrored pair. RAID Level 1 requires a minimum of 2 drives to implement.
Characteristic & Advantages
One Write or two reads possible per mirrored pair
Twice the Read transaction rate of single disks, same Write transaction rate as single disks
100% redundancy of data means no rebuild is necessary in case of a disk failure, just a copy to the replacement disk
Transfer rate per block is equal to that of a single disk & Under certain circumstances, RAID 1 can sustain multiple simultaneous drive failures
Simplest RAID storage subsystem design & Highest disk overhead of all RAID types (100%) – inefficient
Typically the RAID function is done by system software, loading the CPU/Server and possibly degrading throughput at high activity levels. Hardware implementation is strongly recommended
May not support hot swap of failed disk when implemented in “software”

Disadvantages
Highest disk overhead of all RAID types (100%) – inefficient
Typically, the RAID function is done by system software, loading the CPU/Server and possibly degrading throughput at high activity levels. Hardware implementation is strongly recommended
May not support hot swap of failed disk when implemented in “software”
Recommended Product
  • · Accounting
  • · Payroll
  • · Financial
  • · Any application requiring very high availability.
Each bit of data word is written to a data disk drive (4 in this example: 0 to 3). Each data word has  its Hamming Code ECC word recorded on the ECC disks. On Read, the ECC code verifies correct data or corrects single disk errors.
Characteristic & Advantages
“On the fly” data error correction
Extremely high data transfer rates possible
The higher the data transfer rate required, the better the ratio of data disks to ECC disks
Relatively simple controller design compared to RAID levels 3,4 & 5
Very high ratio of ECC disks to data disks with smaller word sizes – inefficient
Entry level cost very high – requires very high transfer rate requirement to justify
Transaction rate is equal to that of a single disk at best (with spindle synchronization)
No commercial implementations exist / not commercially viable
Disadvantages
Very high ratio of ECC disks to data disks with smaller word sizes – inefficient
Entry level cost very high – requires very high transfer rate requirement to justify
Transaction rate is equal to that of a single disk at best (with spindle synchronization)
No commercial implementations exist / not commercially viable
The data block is subdivided (“striped”) and written on the data disks. Stripe parity is generated on Writes, recorded on the parity disk and checked on Reads.
RAID Level 3 requires a minimum of 3 drives to implement
Characteristic & Advantages
Very high Read data transfer rate & Very high Write data transfer rate
Disk failure has an insignificant impact on throughput
Low ratio of ECC (Parity) disks to data disks means high efficiency
Disadvantages
Transaction rate equal to that of a single disk drive at best (if spindles are synchronized) Controller design is fairly complex
Very difficult and resource intensive to do as a “software” RAID

Recommended Application
  • · Video Production and live streaming
  • · Image Editing
  • · Video Editing
  • · Prepress Applications
  • · Any application requiring high throughput

Each entire block is written onto a data disk. Parity for same rank blocks is generated on Writes,                               recorded on the parity disk and checked on Reads.
RAID Level 4 requires a minimum of 3 drives to implement
Characteristic & Advantages
Very high Read data transaction rate
Low ratio of ECC (Parity) disks to data disks means high efficiency
High aggregate Read transfer rate

Disadvantage
Quite complex controller design
Worst Write transaction rate and Write aggregate transfer rate
Difficult and inefficient data rebuild in the event of disk failure
Block Read transfer rate equal to that of a single disk
Each entire data block is written on a data disk; parity for blocks in the same rank is generated on Writes, recorded in a distributed location and checked on Reads.
RAID Level 5 requires a minimum of 3 drives to implement
Characteristic & Advantages
Highest Read data transaction rate
Medium Write data transaction rate
Low ratio of ECC (Parity) disks to data disks means high efficiency
Good aggregate transfer rate
Disadvantage
Disk failure has a medium impact on throughput
Most complex controller design
Difficult to rebuild in the event of a disk failure (as compared to RAID level 1)
Individual block data transfer rate same as single disk
Recommended Application
  • File and Application servers
  • Database servers
  • Web, E-mail, and News servers
  • Intranet servers
  • Most versatile RAID level

Two independent parity computations must be used in order to provide protection against double disk failure. Two different algorithms are employed to achieve this purpose.
RAID Level 6 requires a minimum of 4 drives to implement
Characteristic & Advantages
RAID 6 is essentially an extension of RAID level 5 which allows for additional fault tolerance by using a second independent distributed parity scheme (dual parity)
Data is striped on a block level across a set of drives, just like in RAID 5, and a second set of parity is calculated and written across all the drives; RAID 6 provides for an extremely high data fault tolerance and can sustain multiple simultaneous drive failures
Perfect solution for mission critical applications
Disadvantage
More complex controller design
Controller overhead to compute parity addresses is extremely high
Write performance can be brought on par with RAID Level 5 by using a custom ASIC for computing Reed-Solomon parity
Requires N+2 drives to implement because of dual parity scheme

Recommended Application
  • File and Application servers
  • Database servers
  • Web and E-mail servers
  • Intranet servers
  • · Excellent fault-tolerance with the lowest overhead
RAID Level 10 requires a minimum of 4 drives to implement
Characteristic & Advantages
RAID 10 is implemented as a striped array whose segments are RAID 1 arrays
RAID 10 has the same fault tolerance as RAID level 1
RAID 10 has the same overhead for fault-tolerance as mirroring alone
High I/O rates are achieved by striping RAID 1 segments
Under certain circumstances, RAID 10 array can sustain multiple simultaneous drive failures
Excellent solution for sites that would have otherwise gone with RAID 1 but need some additional performance boost
Disadvantage
Very expensive / High overhead
All drives must move in parallel to proper track lowering sustained performance
Very limited scalability at a very high inherent cost

Recommended Application
  • Database server requiring high performance
    and fault tolerance
RAID Level 50 requires a minimum of 6 drives to implement
Characteristic & Advantages
RAID 50 should have been called “RAID 03″ because it was implemented as a striped (RAID level 0) array whose segments were RAID 3 arrays (during mid-90s)
Most current RAID 50 implementation is illustrated above
RAID 50 is more fault tolerant than RAID 5 but has twice the parity overhead
High data transfer rates are achieved thanks to its RAID 5 array segments
High I/O rates for small requests are achieved thanks to its RAID 0 striping
Maybe a good solution for sites who would have otherwise gone with RAID 5 but need some additional performance boost.
Disadvantages
Very expensive to implement
All disk spindles must be synchronized, which limits the choice of drives.
Failure of two drives in one of the RAID 5 segments renders the whole array unusable

RAID Level 0+1 requires a minimum of 4 drives to implement

Characteristic & Advantages
RAID 0+1 is implemented as a mirrored array whose segments are RAID 0 arrays
RAID 0+1 has the same fault tolerance as RAID level 5
RAID 0+1 has the same overhead for fault-tolerance as mirroring alone
High I/O rates are achieved thanks to multiple stripe segments
Excellent solution for sites that need high performance but are not concerned with achieving maximum reliability
Disadvantage
RAID 0+1 is NOT to be confused with RAID 10. A single drive failure will cause the whole array to become, in essence, a RAID Level 0 array
Very expensive / High overhead
All drives must move in parallel to proper track lowering sustained performance
Very limited scalability at a very high inherent cost

Recommended Application
  • Imaging applications
  • · General fileserver


source :http://yourcomputer.in
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