Among the common RAID levels there are two that are typically seen as the most secure. RAID 5 and RAID 6 both provide protection from drive failures, but which one is the most secure?
This RAID configuration is considered the most common secure RAID level. RAID 5 pairs data parity and with disk striping. This configuration requires a minimum of three drives to work, two for data striping and one for a parity checksum of the block data. By having parity data, the server can recalculate data that is lost in the event of a drive failure.
A RAID 6 configuration is very similar to RAID 5 except that it has parity data written on two drives. This means that you'll need four drives to run this configuration but adds the protection of being able to withstand two simultaneous drive failures.
While both RAID 5 and RAID 6 provide data protection through a combination of data parity and disk striping, RAID 6 wins this match up because of its ability to withstand two simultaneous drive failures. While this is a rare occurrence, if you were to experience two simultaneous failures with RAID 5 you would still lose your data whereas with RAID 6 you will still be able to recover your data.