RAID stands for Redundant Array OF Independent Discs, which is a data storage technology that combines multiple physical disk drives into a single logical unit for the purpose of data redundancy or even both.
TYPES OF RAID SYSTEMS
1) Software RAID: RAID system that doesn’t require a dedicated hardware RAID controller. The RAID compatibility depends on the operating system. It applies whereby there is a single disk with two partitions; one to boot from and the other for data storage.
2) Hardware/Physical RAID: RAID controllers are required in this setup. This controllers support different levels of RAID and also specify the kinds of disks to be used in the array; SSD, SATA OR SAS.
LEVELS OF RAID
RAID 0: Consists of stripping, without mirroring of parity. The capacity of this level of RAID is the sum of all the disks in the set. Failure of one disk in the set causes loss of the entire RAID and the chances of data recovery are minimized.
RAID 1: Consists of data mirroring, without parity or stripping. Data is written identically to two or more drives therefore producing a mirrored set of drives in the set.
RAID 2: Consists of bit-level stripping whereby data is stripped in a way that each sequential bit is on a different drive.
RAID 3: Consists of byte-level stripping whereby data is stripped in a way that each sequential byte is on a different drive.
RAID 4: Consists of block-level stripping with dedicated parity whereby the read/write operations do not spread across all data drives.
RAID 5: Consists of block-level stripping with distributed parity whereby the parity info is distributed among all drives requiring all drives but one to be present to operate. Upon failure of a single drive, subsequent reads can be calculated from the distributed parity such that no data is lost.
RAID 6: Consists of block-level stripping with double distributed parity. This provides fault tolerance of up to two failed drives.
Nested (Hybrid) RAID: Many controllers allow RAID levels to be nested. The elements of RAID may be individual drives or arrays by themselves.
Note: Attempting to recover a RAID without an unexperienced data recovery specialist can put your critical data at further risk. When hardware malfunction is a component of the problem, permanent destruction of data can occur with failed recovery attempts.
With alot of experience on Raid recovery and through our advanced and up to date technology. East Africa Hi Tech Solutions has the capacity and technical expertise required to solve complex, technically challenging RAID recoveries.