- 3 or more drives
- RAID array shows up as a single volume on the desktop.
- Store music, photos, videos
- Anything that takes time to create
- Anything that is difficult to replace
- Anyone needing faster data rates
With RAID 5, data is striped for speed like a RAID 0, but a duplication or parity is built in to protect your data from a single drive failure. This results in fast performance comparable to a RAID 0, but with the added benefit of protection.
The storage space resulting from a RAID 5 array is:
the sum of all the drives put together minus one drive worth of space.
RAID 5 incorporates striping of data just like in a RAID 0 array, however, in a RAID 5 there are redundant pieces of the data that are also distributed across the drives and are referred to as parity. Having the parity blocks staggered across each drive allows any single drive in the RAID 5 array to fail without any data loss.
In the illustration below there are 4 drives set up as a RAID 5.
Each colored square is a “block” of data. All blocks are the same size.
- The first data block of the mp3 file is represented as:
- The second data block is represented as:
- And the third data block is represented as:
- Each of those three data blocks have a certain number of bits that are 1’s & 0’s. Those values are then summed up as a value on the parity block represented by on Drive 4.
- Like an algebraic equation, you can solve the equation when you have a missing piece, in this case a missing piece would occur when you have a failed drive.