Friday, November 20, 2020

Raid concept - How to deal with RAID concepts in interview persective?

 Raid concept - How to deal with RAID concepts from an interview perspective?


RAID (Redundant Array of Independent Disks)

 

RAID 0 -  RAID 1 -  RAID 5 -  RAID 10

 

RAID 0 (Striping)

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Not fault tolerance

Data is striped across multiple disks

The data will be lost if one of the disk got corruped/destroyed.

 

RAID 1 (Mirroring and Duplexing)

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Fault tolerant

Data is copied on more than one disk

Each disk has the same data (data is safe)

 

RAID 5  (Striping with parity)

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Requires 3 or more disks

commonly used and It can store large amount of data and raid 5 is fast

Data is 'striped' across multiple disks along with parity (Parity is used to rebuild the data in the event of disk failure.)

 

RAID 10 (RAID 1+0)

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Combines Raid 1 and Raid 0

Need to use minimum of 4 disks

Two disks is mirrored using raid 1 setup (Both sets of 2 disks are striped using raid 0 setup)

Benefits from the fault tolerance of raid 1 and speed of raid 0

The disadvantage is - can only use 50% for data storage

 

(BTW, Fault tolerance refers to the ability of a system (computer, network, cloud cluster, etc.) to continue operating without interruption when one or more of its components fail.)