SAN jobs interview questions - Storage Area Networking job interviews Series 2

SAN jobs interview questions - Storage Area Networking job interviews Series 2
Below are the 10 questions asked in an interview with SAN company StorageTek .
1) Which are the SAN topologies?

Answer :SAN can be connected in 3 types which are mentioned below:
Point to Point topology
FC Arbitrated Loop ( FC :Fibre Channel )
Switched Fabric

2) Which are the 4 types of SAN architecture types
Answer :Core-edge
Full-Mesh
Partial-Mesh
Cascade

3) which command is used in linux to know the driver version of any hardware device ?
Answer : dmesg

4) How many minimum drives are required to create R5 ( RAID 5) ?

Answer : You need to have at least 3 disk drives to create R5.

5) Can you name some of the states of RAID array ?

Answer : There are states of RAID arrays that represent the status of the RAID arrays which are given below
online
Degraded
Rebuilding
Failed

6) Name the features of SCSI-3 standard ?

Answer : QAS: Quick arbitration and selection
Domain Validation
CRC: Cyclic redundancy check

7) Can we assign a hot spare to R0 (RAID 0)array?

Answer :No, since R0 is not redundant array, failure of any disks results in failure of the entire array so we cannot rebuild the hot spare for the R0 array.

8) Can you name some of the available tape media types ?

Answer :There are many types of tape media available to back up the data some of them are
DLT :digital linear tape - technology for tape backup/archive of networks and servers; DLT technology addresses midrange to high-end tape backup requirements.
LTO :linear tape open; a new standard tape format developed by HP, IBM, and Seagate.
AIT :advanced intelligent tape; a helical scan technology developed by Sony for tape backup/archive of networks and servers, specifically addressing midrange to high-end backup requirements.

9) what is HA ?

Answer : HA High Availability is a technology to achive failover with very less latency. Its a practical requirement of data centers these days when customers expect the servers to be running 24 hours on all 7 days around the whole 365 days a year - usually referred as 24x7x365. So to achieve this a redundant infrastructure is created to make sure if one database server or if one app server fails there is a replica Database or Appserver ready to takeover the operations. End customer never experiences any outage when there is a HA network infrastructure.

10) What is virtualization?

Answer :Virtualization is logical representation of physical devices. It is the technique of managing and presenting storage devices and resources functionally, regardless of their physical layout or location.Virtualization is the pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. Storage virtualization is commonly used in a storage area network (SAN). The management of storage devices can be tedious and time-consuming. Storage virtualization helps the storage administrator perform the tasks of backup, archiving, and recovery more easily, and in less time, by disguising the actual complexity of the SAN.