Raid arrays are arrangements of storage disks in certain configurations having their own advantages and disadvantages.
RAID Level 0 – Striping
Data is spit into parts and each part gets written to a disk. This way the read and write speed is increasy multiple times. The disadvantage is that even if one the disk gets corrupted, the other disks are also rendered useless.
RAID Level 1 – Mirroring
In this setup data is written to two disks simultaneously. This enables data to be fetched from the other disk if one of the disks fail.
RAID Level 5
It requires at least 3 disks but can also work with upto 16 disks. In this case one of the disk is used to store the pairity of other two disks. That way if one of the disks faile the other disks can be used to recalculate the data of the lost disk.
RAID level 6 – Striping with double parity
RAID 6 is similar to RAID 5 except for the fact that pairity data is written to two drives. This way the array can hadle the failure of two disks simultaneously.
RAID level 10 – combining RAID 1 & RAID 0
RAID 10 is better read as “raid one, zero” because it is essentially a combination of RAID 1 and RAID 0. It combines their advantages and disadvantages.
Basically it requires minimum of 4 disks where two pars are pairs of raid 0 (stripping) and pair 1 and pair 2 are mirrors of each other.