View source for RAID 5

== RAID 5 ==
'''RAID 5''' (''Redundant Array of Independent Disks, Level 5'') is a storage configuration that provides data redundancy and improved read performance through the use of block-level striping with distributed parity.

It requires a minimum of '''three disks''' and can tolerate the failure of '''one disk''' without data loss.

=== How It Works ===

RAID 5 stripes data across all disks and stores parity information (used for recovery) distributed evenly among all disks. If a single disk fails, the system can reconstruct the lost data using the remaining data and parity.

{| class="wikitable"
! Disk 1 !! Disk 2 !! Disk 3 !! Disk 4
|-
| Data A || Data B || Parity AB || Data C
|-
| Data D || Parity CD || Data E || Data F
|}

=== Advantages ===

* Efficient storage utilization (usable capacity = N-1 disks)
* Good read performance
* Fault tolerance for one disk failure
* More storage-efficient than RAID 1 or RAID 10

=== Disadvantages ===

* Slower write performance due to parity calculations
* Recovery after failure can be slow and risky (especially on large disks)
* Vulnerable to data loss if a second disk fails during rebuild

=== Common Use Cases ===

* File servers
* Archival storage
* Medium-performance systems with redundancy requirements

=== See Also ===

* [[RAID]]
* [[RAID 6]]
* [[RAID-Z1]]