This level uses byte level striping with dedicated parity. In other words, data is striped across the array at the byte level with one dedicated parity drive holding the redundancy information. The idea behind this level is that striping the data increasing performance and using dedicated parity takes care of redundancy. 3 hard drives are required. 2 for striping, and 1 as the dedicated parity drive. Although the performance is good, the added parity does slow down writes. The parity information has to be written to the parity drive whenever a write occurs. This increased computation calls for a hardware controller, so software implementations are not practical. RAID 3 is good for applications that deal with large files since the stripe size is small. Since this level is so rare, we have not come up with a recovery procedure for this RAID level. Recovery is possible by finding the parity disk using the image compression technique, then removing it and treating the RAID as a stripe.
RAID 3 Data Recovery
