RAID is short for: redundant array of independent disks.

RAID (redundant array of independent disks) is a way of storing the same data in different places on multiple hard disks or solid-state drives (SSDs) to protect data in the case of a drive failure.

Depending on the capability of the array of hard-drives and it’s controller, there are several RAID levels that can be set.

For example, a common drive that is used in produciton is a 4 Bay Sandisk Pro RAID (24TB). below highlights the effects of each configuration.

RAID 0: Data is written to all four drives, there is no redundancy if a drive were to fail. This level is typically reserved for drives that need the fastest read and write performance.

RAID 1: Consists of a mirror of the drives within an array, there is are no parity calcuations or striping. A performance and storage penalty is incurred for reading and writing.

RAID 5: One drive out of the 4 is reserved for parity and striping, this is a redundant drive that should any of the other drives fail the data set can be rebuilt. Total storage is decreased by the size of parity drive. Performance is also decreased slightly in write operations.

RAID 6: Extends on RAID 5 to add a second parity drive, in favour of sacrificing storage and performance._

RAID 10: This is a combination of RAID 1 and 0 in which two drives may operate in RAID 0 whilst the other two act a a mirror.