RAID 5 data recovery
RAID 5 is one of the most popular RAID level, on this level both data and parity information are striped across three or more drives. The only change comparing to RAID 4 is that parity disc known from RAID 4 has been exchanged into distributed parity algorithm that is responsible for writing data parity blocks across all the drives in the array. The usage of the algorithm removes bottleneck effect that was one of the biggest limitation of RAID 3 and 4. The matrix array performance can be adjusted bay using different stripe sizes.
Controller Requirements: medium to high end hardware RAID card, also supported by some operating systems as a software RAID
Hard Disk Requirements: minimum 3 hard drives, maximum is set by controller, all the discs should be the same size.
Array Capacity: size of the smallest drive*(number of drives -1)
Storage Efficiency: (number of drives -1)/number of drives
Fault tolerance: good, loss of one drive can be tolerated
Availability: very good, most of controllers support automatic rebuild and hot sparing
Degradation and rebuilding: degradation can be substantial after failure or during rebuild because of distributed parity
Random read performance: very good
Random write performance: poor overhead is substantial
Sequential read performance: very good
Sequential write performance: fair good
Some of our recent Data Recovery Cutomers
