Which RAID level can handle two simultaneous disk failures and achieve parity?

The answer is RAID 6 because it is specifically designed to handle two simultaneous disk failures while providing parity for data recovery. RAID 6 utilizes double parity, meaning it writes two sets of parity data across the drives in the array. This feature allows it to sustain the loss of two disks without compromising data integrity.

In a RAID 6 configuration, if one disk fails, the system can continue to function normally and reconstruct the lost data using the remaining disks and the parity information. If a second disk fails during this time, the array can still recover data using the remaining disks and the additional parity. This makes RAID 6 an excellent option for systems where data availability and fault tolerance are critical.

Other RAID levels, such as RAID 5, can handle a single disk failure but not two, which limits its fault tolerance compared to RAID 6. While RAID 0+1 and RAID 2 have their own structures and redundancy methods, they do not offer the same level of protection against multiple simultaneous failures as RAID 6 does. Thus, the choice of RAID 6 ensures greater resilience for critical data storage scenarios.