Which statement best describes RAID Level 1?

Which statement best describes RAID Level 1?

• A. Data mirrored on two drives; if one drive fails, data remains available.
• B. Data striped with parity across drives.
• C. Data stored across multiple drives with distributed parity.
• D. Data stored on a single drive with a separate backup.

Answer: (B)

RAID level 1 achieves fault tolerance by mirroring data on two drives, so both drives hold identical copies. If one drive fails, the system can continue to operate from the remaining drive without data loss. This setup requires at least two disks and provides simple recovery. Because the data is duplicated, usable capacity equals the size of one disk, and reads can be served from either disk, improving read performance, while writes must be applied to both disks, so write performance is similar to a single drive. The other descriptions refer to striping with parity (RAID 5/6) or a non-RAID backup strategy, which are not RAID 1.

RAID level 1 achieves fault tolerance by mirroring data on two drives, so both drives hold identical copies. If one drive fails, the system can continue to operate from the remaining drive without data loss. This setup requires at least two disks and provides simple recovery. Because the data is duplicated, usable capacity equals the size of one disk, and reads can be served from either disk, improving read performance, while writes must be applied to both disks, so write performance is similar to a single drive. The other descriptions refer to striping with parity (RAID 5/6) or a non-RAID backup strategy, which are not RAID 1.