MJM Data Recovery

RAID 5 Data Recovery When a customer comes to use with a RAID 5 query, it is important that our engineer understands the concept of RAID 5, the different versions and in some cases proprietary variations. A working RAID 5 system will consist of at least 3 drives. The total accessible data are will be the equivalant of the total sum of n -1 times the size of the smallest of the drives in array) so if we build a RAID 5 array that has 4 x 36 Gb drives the size of the array would be 36 x (4-1) which gives 36 x 3 = 108 Gbytes. The remaining 36 Gb is used to calculate parity this is done using XOR calculations For RAID 5 there is a parity block that shifts its position in the array for each stripe.. The diagram above shows our 4-drive raid 5 array with the Parity block (p) marked in each stripe (A, B, C, D) and Data blocks marked A1, A2 ... through .. D2, D3 Lets explain this a bit more clearly. In the above array it shows the first four stripes or rows (A B C