Interview questions on Fiber Channel & Storage Technology

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Compaq Fibre Channel Storage Array RA4000

Thanks to one of our blog reader Rahman for contributions of below interview questions on fiber channel.
1.WHAT ARE THE BENEFITS OF FIBRE CHANNEL SANS?

Fibre Channel SANs are the de facto standard for storage networking in the corporate data center because they provide exceptional reliability, scalability, consolidation, and performance. Fibre Channel SANs provide significant advantages over direct-attached storage through improved storage utilization, higher data availability, reduced management costs, and highly scalable capacity and performance.


2.WHAT ENVIRONMENT IS MOST SUITABLE FOR FIBRE CHANNEL SANS?

Typically, Fibre Channel SANs are most suitable for large data centers running business-critical data, as well as applications that require high-bandwidth performance such as medical imaging, streaming media, and large databases. Fibre Channel SAN solutions can easily scale to meet the most demanding performance and availability requirements.

3.WHAT CUSTOMER PROBLEMS DO FIBRE CHANNEL SANS SOLVE?

The increased performance of Fibre Channel enables a highly effective backup and recovery approach, including LAN-free and server-free backup models. The result is a faster, more scalable, and more reliable backup and recovery solution. By providing flexible connectivity options and resource sharing, Fibre Channel SANs also greatly reduce the number of physical devices and disparate systems that must be purchased and managed, which can dramatically lower capital expenditures. Heterogeneous SAN management provides a single point of control for all devices on the SAN, lowering costs and freeing personnel to do other tasks.

4.HOW LONG HAS FIBRE CHANNEL BEEN AROUND?

Development started in 1988, ANSI standard approval occurred in 1994, and large deployments began in 1998. Fibre Channel is a mature, safe, and widely deployed solution for high-speed (1Gb, 2Gb, 4Gb) communications and is the foundation for the majority of SAN installations throughout the world.


5.WHAT IS THE FUTURE OF FIBRE CHANNEL SANS?

Fibre Channel is a well-established, widely deployed technology with a proven track record and a very large installed base, particularly in highperformance, business-critical data center environments. Fibre Channel SANs continue to grow and will be enhanced for a long time to come.The reduced costs of Fibre Channel components, the availability of SAN kits, and the next generation of Fibre Channel (4Gb) are helping to fuel that growth. In addition, the Fibre Channel roadmap includes plans to double performance every three years

6.WHAT ARE THE BENEFITS OF 4GB FIBRE CHANNEL?

Benefits include twice the performance with little or no price increase, investment protection with backward compatibility to 2Gb, higher reliability due to fewer SAN components (switch and HBA ports) required, and the ability to replicate, back up, and restore data more quickly. 4Gb Fibre Channel systems are ideally suited for applications that need to quickly transfer large amounts of data such as remote replication across a SAN, streaming video on demand, modeling and rendering, and large databases. 4Gb technology is shipping today.


7.HOW IS FIBRE CHANNEL DIFFERENT FROM ISCSI?

Fibre Channel and iSCSI each have a distinct place in the IT infrastructure as SAN alternatives to DAS. Fibre Channel generally provides high performance and high availability for business-critical applications, usually in the corporate data center. In contrast, iSCSI is generally used to provide SANs for business applications in smaller regional or departmental data centers.

8.WHEN SHOULD I DEPLOY FIBRE CHANNEL INSTEAD OF ISCSI?

For environments consisting of high-end servers that require high bandwidth or data center environments with business-critical data, Fibre Channel is a better fit than iSCSI. For environments consisting of many midrange or low-end servers, an IP SAN solution often delivers the most appropriate price/performance.

- You Can Write/Contribute & Win Some COOL Stuff
- Know Basically What is Storage Area Network
- If You want a High Paying Job what should be your Strategy.
- It has more than 90 interview questions listed in this single blog
Interview questions series 1
Interview questions series 2
Interview questions series 3
Interview questions series 4
Interview questions series 5
Interview questions series 6
Interview questions series 7
Interview questions series 8
Interview questions series 9
Interview questions series 10
- Know what happens in office routine of a Storage professional
- Know what sort of job roles are there in Storage area networking
- Know what they ask in a storage job interview
- Need guidance to revamp or improve your Resume
- It has one simple storage implementation Case study
- Basic questions a Software job hunter asks
- Answers for the questions like Job Opportunities in Storage
- Want to see details of Job requirement for Storage
- U like to take a Virtual tour of Cisco Production Data Center
- Every one talks about HA or High Availability - should'nt You
- Dont forget that Career in Any field requires dedication and hard work - U can do it Dude

FOR PREVIOUS POSTS CLICK THIS LINK

Network Attached Storage Introduction

What is NAS (Network Attached Storage)

In a NAS architecture, corporate information resides in a storage system that is attached to a dedicated server, which in turn is directly connected to a network, and uses a common communications protocol, such as TCP/IP. In a corporate IT infrastructure, the NAS operates as a server in a typical client/server environment. The NAS is connected to a network by standard connectivity options such as Ethernet, FDDI and ATM. In some cases, a single specialized NAS server can have up to 30 Ethernet connections.

A NAS server (a processor with an operating system) is necessary in order to transfer the data between it and the NAS storage device, and then move the data on to the corporate network. This is done via traditional file I/O protocol. The most common of these protocols are Network File System (NFS) and Common Internet File Service (CIFS).

NFS was originally developed by Sun Microsystems and is now part of the Open Network Computing (ONC) initiative. It is the most common file access protocol to access shared files in a UNIX environment. CIFS is a file access protocol designed for the Internet, and based on the Server Message Block (SMB) protocol used by the Microsoft Windows operating system. CIFS does not replace the use of NFS, but rather complements it, because of its ability to provide synchronization between client and server.

Although a NAS with NFS can be implemented on readily available tightly-coupled server and disk storage arrays, there are actually only three (3) major vendors that currently have a large marketshare of the NAS marketspace. They are: Network Appliance (also known as NetApps), Auspex Systems, and Sun Microsystems. Both NetApps and Auspex use proprietary tightly integrated servers and storage devices. In the majority of cases, the Sun implementation uses a dedicated Sun server, and typically connected to external Sun storage; although any external storage that is certified to be connected to a Sun server can also be used. However, this is not the case with NetApps or Auspex, as additional storage requirements must be acquired from the respective NAS vendor.

The NAS server permits multiple clients to share files, since clients can access files as if they were local files, with the exception that they must be accessed over a network. In this way, common files can be maintained in a central location, and accessed by many clients, which eliminates the need for multiple copies of files on multiple client systems. In addition, this improves data integrity, data security and reduces costly duplication of files. Major applications that benefit from the use of NAS to share large amounts of information include CAD/CAM (Computer Aided Design/Computer Aided Manufacturing), document management, imaging as well as other similar application serving environments.


Because data travels over the network, NAS is not always suitable for applications such as data warehouses and On-Line Transaction Processing (OLTP), since these applications need to sustain high I/O data rates with little, or no degradation in response times to the clients.

- You Can Write/Contribute & Win Some COOL Stuff
- Know Basically What is Storage Area Network
- If You want a High Paying Job what should be your Strategy.
- It has more than 90 interview questions listed in this single blog
Interview questions series 1
Interview questions series 2
Interview questions series 3
Interview questions series 4
Interview questions series 5
Interview questions series 6
Interview questions series 7
Interview questions series 8
Interview questions series 9
Interview questions series 10
- Know what happens in office routine of a Storage professional
- Know what sort of job roles are there in Storage area networking
- Know what they ask in a storage job interview
- Need guidance to revamp or improve your Resume
- It has one simple storage implementation Case study
- Basic questions a Software job hunter asks
- Answers for the questions like Job Opportunities in Storage
- Want to see details of Job requirement for Storage
- U like to take a Virtual tour of Cisco Production Data Center
- Every one talks about HA or High Availability - should'nt You
- Dont forget that Career in Any field requires dedication and hard work - U can do it Dude

FOR PREVIOUS POSTS CLICK THIS LINK

Network Attached Storage Videos,Tutorial & Interview questions

EMAIL roger.smithson@gmail.com FOR A FREE SAN STUDENT GUIDE PDF

Here are some real informative Videos on Network attached Storage & some more interview questions on NAS.

Some of the more general yet essential interview questions on NAS are:
1.What is NAS?
2.When NAS is a better solution as a storage requirement?
3.Whats the difference between NAS & SAN ?
4.What are the advantages & Disadvantages of NAS ?
5.How can a NAS implementation be improved over performance ?
6.Mention some case study on NAS implementation ?
7. Is it possible to setup a NAS using very basic PC equipment ?
8. Which are the best NAS vendors & what are their focu products?
9. How NAS-DAS-SAN differ ?
10. Can u explain a NAS Gateway in detail ?

Answers for all these questions will follow in next posting with more photos & Videos.

Answers to Interview Questions on Veritas Volume Manager

EMAIL roger.smithson@gmail.com & GET FREE SAN TUTORIAL GUIDE.(PDF:124 PAGES)

Thanks to Ashish Pathak for all the questions and also answers to Interview questions on Veritas Volume Manager.

# Name the mandatory disk group in VxVM 3.5 ? How will you configure VxVM in 3.5 ?
ANS: rootdg is the mandatory disk group in VxVM 3.5, vxinstall is the command to configure VxVM, It will create the disk groups, initializes the disks and adds them to the group.

# How will you create private and shared disk group using VxVM ?
ANS: For Private DG:
Command: vxdg init

For Shared DG:
Command: vxdg -s init < disk1 disk2 disk3 >

# Which are the different layouts for volumes in VxVM ?
ANS: mirror, stripe, concat (default one), raid5, stripe-mirror, mirror-stripe.

# What is the basic difference between private disk group and shared disk group ?
ANS: Private DG: The DG which is only visible for the host on which you have created it, if the host is a part of cluster, the private DG will not be visible to the other cluster nodes.
Shared DG: The DG which is sharable and visible to the other cluster nodes.

# How will you add new disk to the existing disk group ?
ANS: Run vxdiskadm command, which will open menu driven program to do various disk operations, select add disks option or you can use another command vxdiskadd.

# How will you grow/shrink the volume/file system ? What is the meaning of growby and growto options ? What is the meaning on shrinkto and shrinkby options ?
ANS: vxassist command is used to do all volume administration, following is the description and syntax.

Growby option: This is will grow your file system by adding new size to the existing file system.

Growto option: This will grow your file system as per the new size. This WILL NOT ADD new size to the existing one.

Shrinkby option: This will shrink your file system by reducing new size from existing file system.

Shrinkto option: This will shrink your file system as per the new size. This WILL NOT REDUCE the file system by reducing new size.

Command:
vxassist -g [growto, growby, shrinkto, shrinkby] length

# How will you setup and unsetup disks explicitly using VxVM ?
ANS: You can use /etc/vx/bin/vxdiskunsetup to unsetup the disk, and /etc/vx/vxdisksetup to setup the disk.

# How will you list the disks, which are in different disk groups ?
ANS: vxdisk list is the command will list the disks from the DG which is currently imported, you can check the same using vxprint command too. vxdisk -o alldgs list command list all the disks which are in different dg's.

# What is the private region in VxVM ?
ANS: Private region stores the structured VxVM information, it also stores the disk ID and disk geometry. In short words it has metadata of the disk.

# If, vxdisk list command gives you disks status as "error", what steps you will follow to make the respective disks online ?
ANS: If you faced this issue because of fabric disconnection then simply do vxdisk scandisks, otherwise unsetup the disk using using /etc/vx/bin/vxdiskunsetup and setup the disks again using /etc/vx/bin/vxdisksetup, this will definitely help! [ /etc/vx/bin/vxdiskunsetup will remove the private region from the disk and destroys data, backup the data before using this option]

I am greatly thankful to Ashish Pathak ashish.rp AT gmail.com for emailing & contributing this real interview questions on Veritas Volume Manager