What Is RAID 60?

A RAID 60 array combines the block-level striping of RAID level 0 with the dual parity of RAID level 6. It has the same multilevel disk set as RAID 6 but supports more drives. RAID 60 is also referred to as RAID 6+0 and offers dual drive failure protection. When it comes to protecting against multiple drive failures, there are two basic types of security: mirroring and parity. In mirroring, two or more drives are used to store identical copies of data; in likeness, each block has an additional bit stored elsewhere on the disk that indicates whether the block is valid. Mirroring protects against single-disk failure only; parity protects against single and double-disk failure (two drives failing simultaneously). RAID 10 combines mirroring and striping to improve performance over either approach alone. RAID 60 combines striping with dual parity for even better protection against double disk failures. Still, at a cost: You can only use a maximum of 8 disks for a given array before it becomes unwieldy to manage. RAID 60 is like a party. It's fun, it's loud, and it's got many people in it. RAID 60 is also the best way to get the most bang for your buck, but you've got to know how to make it work. RAID 60 requires at least eight disks or four-disk RAID 6 sets to be constructed. If you build a RAID 60 set, you must have at least eight disks or four-disk RAID 6 sets available for use. That's because RAID 60 can continue operations even if it loses two disks in a parity set (parity set of four disks each). It also means that because multiple locations of parity information exist on each block, write performance slows down and consumes more disk space than other RAID levels. But don't worry: you will get what you need from it! Add another eight disks or four-disk RAID 6 sets, and your write performance will improve!