Definition - What does RAID 60 mean?
RAID 60 is a type of nested RAID level that combines the block-level stripping feature of RAID level 0 with the dual parity of RAID level 6. It has the same multi-level disk set as of RAID 6, but supports more drives.
RAID 60 is also known as RAID 6+0 and dual drive failure protection.
Techopedia explains RAID 60
RAID 60 must be implemented on a minimum of eight disks or a set of four-disk RAID 6 sets to be constructed that can support up to 128 drives. As with RAID 6, RAID 60 also can continue operations even if it loses two disks in a parity set (parity set of four disks each). RAID 60 provides better utilization but has lower write performance as it has to write more than other RAID levels. RAID 60 also consumes more disk space for parity information as it creates multiple sets of parity information on each block.