RAID 5 provides fault tolerance by distributing parity across disks.

• A. RAID Level 0
• B. RAID Level 1
• C. RAID Level 5
• D. RAID Level 3

Answer: (C)

Understanding how fault tolerance works in RAID starts with parity and how data is laid out. RAID 0 has no redundancy, so it offers no fault tolerance. RAID 1 mirrors all data, providing redundancy through duplication but not parity across drives. RAID 3 uses a dedicated parity disk, which means parity isn’t distributed. RAID 5 stripes data and parity across all disks at the block level, so parity blocks are spread across every drive rather than residing on a single disk. If any one disk fails, the missing data can be reconstructed from the remaining data blocks and the corresponding parity from the other disks. This distribution of parity across the array gives fault tolerance with efficient use of storage, which is why RAID 5 is the correct description. In other words, the ability to survive a single disk failure while using storage efficiently hinges on parity distributed across all disks.