RAID-5 is shorthand for RAID Level 5: Independent data disks with distributed parity blocks.

RAID Level 5 is a type of RAID configuration which uses 3 or more disks to provide redundancy in case of a drive failure, combined with striping to increase read/write speed.

Parity bits are scattered over all disks.


  • Availability: Can tolerate the loss of 1 drive
  • Capacity: 66% or higher (3 drives = 2 drive available space, 4 drives = 3 drive available space)
  • Degradation: Performance decreases substantially until the failed drive is replaced and rebuilt
  • Performance: Highest read speed (up to 3x single disk), medium write speed
  • Summary: Combination of good performance, good fault tolerance, high storage efficiency
  • Typical Uses: File and application servers, databases, web, email servers, intranet servers

How it works

  • READ: read data blocks from 3 or more disks at the same time
  • WRITE: read parity block, write data block, write parity block

Comparison with other RAID types:

  • RAID-0 has faster writes and equal read speed (for a 3-drive RAID-0 set)
  • RAID-1 has faster writes and slower reads

More Information

metawerx specific

referring pages