RAID 6 Configuration Data Recovery
This configuration uses the same basic idea as RAID 5, but creates two separate parity sets. This means it has to have four disks to function, and loses two disks worth of storage space to parity. However, it also means that any two disks can fail, and the array can still be rebuilt. Additionally, RAID 6 (and, to a certain extent, RAID 5) can scale up easily and give very large storage arrays while only losing a small portion of their overall drive space. For example, a 10 disk RAID 6 array would still have 8 disks worth of space and be able to handle two complete disk failures. Reading data from a RAID 6 array is not quite as fast as it would be from a RAID 5 (as there are two parity streams to check), but is still faster than a single disk.
Note: With less expensive, but less reliable SATA disk drives in a configuration that employs RAID 6, it is possible to achieve a higher level of availability than a Fibre Channel Array using RAID 5. This is because the second parity drive in the RAID 6 RAID set can withstand a second failure during a rebuild. In a RAID 5 set, the degraded state and/or the rebuilding time onto a hot spare is considered the window at which the RAID array is most vulnerable to data loss. During this time, if a second disk failure occurs, data is unrecoverable. With RAID 6 there are windows of vulnerability that may require recovery if the second parity drive also fails. See our information regarding RAID 6 Data Recovery.