A system administrator at an enterprise company wants to extend the storage array of a server by using existing older disk drives. Because of the smaller size of the older drives, the administrator ne

RAID 1+0 mirrors data across pairs of drives and can tolerate one failure per mirrored pair, but two simultaneous failures on drives in the same mirror pair will result in data loss.

RAID 3 uses a single dedicated parity drive and can only tolerate the failure of one drive at a time; a second simultaneous failure causes complete data loss.

RAID 5 distributes a single parity block across all drives and can recover from only one drive failure; a second simultaneous drive failure destroys the array and results in data loss.

RAID 6 writes two independent parity blocks across all member drives, so the array can reconstruct data correctly even when any two drives fail at the same time. This dual-parity design is specifically built for environments requiring higher fault tolerance than single-parity RAID levels, and it supports large drive counts such as 18 disks while maintaining full protection against two simultaneous failures.