Raid

Question 1

What is RAID? What are some benefits of using RAID?

Answer 1

Redundant array of independent/inexpensive disk.
The major benefits is that it prevents data loss .
Performance and optimization.

Question 2

Difference between RAID and LVM?

Answer 2

LVM is at software level/operating level, managed by dev mapper.
Raid is ay hardware level, managed by raid controller.

Question 3

Why they exist different levels of RAID?

Answer 3

For redundancy, high availability or optimization.

Question 4

Difference between. RAID 0 and 1?

Answer 4

*Raid 0 is not fault tolerant. The data is not duplicated. It’s just fast.
*Raid 1 is mirroring . Is also fault tolerant, best read intensive.

Question 5

What is difference between RAID 5 & 6 lever?

Answer 5

• RAID 5 is with striping and with parity You need 3 or more disk to use RAID 5. Single parity and faster than RAID 6.
• RAID 6 you need 4 or more disk to use it. Parity is spread twice on all disks. Double parity, slower than 5.

Question 6

What is the benefit of parity?

Answer 6

Reconstruct data from backup (parity)
Rebuild Data in the event of a disk failure.

Question 7

How many disks Raid 6 can lose without losing data?

Answer 7

It can lose 2 disk.

Question 8

What is minimum number of disks you need to configure RAID 5 and RAID 6?

Answer 8

*RAID 5 minimum of 3 or more
*RAID 6 minimum of 4 or more

Question 9

What is RAID 10?

Answer 9

*RAID 10 combines RAID 1 and with 0, you need to use minimum of 4 disk.
* a set of 2 disk are mirrored using a RAID 1 setup. The. Both sets of 2 disks are stripped using RAID 0.
* RAID 10 benefits from fault tolerance of raid 1 and the speed of RAID 0.
*Downside is you can only use 50% of the capacity for Dara storage. So if you are using 4 disks in RAID 10 setup, you can inky use 2 of them for actual storage.

Question 10

If you are allowed to pick any si gle RAID level which level will you pick if cost is basic consideration?

Answer 10

I would pick raid 0 if is really necessary to save the cost and its data is not so sensitive in case of data lost.

Question 11

If you need only better reading feature, then Which level you pick?

Answer 11

RAID 1 offers better reading performance .

Question 12

Is RAID 6 slower than RAID 5?

Answer 12

Yes RAID 6 is slower because it has 2 independent parity blocks instead of 1.