RAID

What is a Striped Volume?

Striping spreads the data for a single volume over two or more drives, with each drive containing only part of the volume being distributed.

What is a Mirrored Volume?

Mirroring uses two or more drives to create a volume protected from drive failure. Unlike Striped Volumes, each drive contains a copy of the entire drive.

What is Parity?

By definition, parity is the “state of being equal.” Parity computations are used in RAID drive arrays for fault tolerance by calculating the data in two drives and storing the results on a third. If a drive fails and is replaced, the RAID controller rebuilds the lost data from the other two volumes.

Dedicated Parity

when the parity information is all stored on a single drive. Distributed Parity spreads the data across all the drives in the array.

RAID 0

Striped, No Mirror.
at least 2 drives
splits the data evenly
providers performance
no redundancy

RAID 1

Mirrored, no stripe. safest RAID,

at least 2 drives
duplicating data
twice as much space
redundant

RAID 4

Striped and Parity. Best for general use on SSDs. Fast and Safe, Super-fast read/write of large files. Requires 3 or more disks

RAID 5

striping with parity
at least 3 drives
high redundancy

RAID 6

striped, Two distributed Parity. Similar to RAID 5, Allows 2 disk failure. Slightly slower than RAID 5 on Writes, no added delays on reads. Requires 4 or more disks.

RAID 10

Fastest and safest RAID Option.
stripe of mirrors
needs 4 drives
speed of striping the redundancy of mirroring

Flash Drives

flash memory
non volatile memory
limited number of writes

Memory Cards

used in phones or cameras