RAID – Speed and Safety for Storage

RAID – Speed and Safety for Storage

The RAID system is the simultaneous use of disks to secure the datas, or increase the reading/editing performances. This technology is 30 years old ! RAID stands for Redundant Array of Independent Disks.

RAID 0

RAID 0
RAID 0 – Datas are scattered on every disk.

RAID 0 benefits from the sum of ready and writting speed of every disk. It is extremely fast. But if one disk fails, you lose every thing. So it is not very secured.

RAID 1

RAID 1
RAID 1 – The datas are identical on both disks.

In RAID 1 the speed of reading/writting is from the slowest disk. It is not very fast. You loose your data if both disks fail. It it very secured.

RAID 5

RAID 5
RAID 5 – Datas are sqattered on every disk with one back up part within each disk to support the failure of one disk

RAID 5 benefits from the speed of reading/writting of almost every disk (-1). It is very fast. It allows one disk to fail. It is secured. 

RAID 6

RAID 6
RAID 6 –  Datas are squattered on every disk with a backup part within each disk to support the failure of 2 disks.

RAID 6 benefits from the speed of reading/writting of almost every disk (-2). It is fast. Allows 2 disks to fail. Very secured.

JBOD

jbod
jbod – Just Bunch Of Disk – Independent disks. Not interesting. 
RAID Levels Compared

RAID controller is either hardware (microchip) either a software (here et here)