RAID level-5 requires a minimum of three physical drives. This RAID level stripes data and parity across all drives in the array. When you assign RAID level-5 to an array, the capacity of the array is reduced by the capacity of one drive (for data-parity storage).
RAID level-5 offers both data protection and increased throughput. RAID level-5 gives you higher capacity than RAID level-1, but RAID level-1 offers better performance.
RAID level-5 requires a minimum of 3 drives and, depending upon the level of firmware and the stripe-unit size, supports a maximum of 8 or 16 drives.
The following illustration is an example of a RAID level-5 logical drive.
Start with four physical drives. | ![]() |
Create an array using three of the physical drives, leaving the fourth as a hot-spare drive. | ![]() |
Then, create a logical drive within that array. | ![]() |
The
data is striped across the drives, creating blocks.
Notice that the storage of the data parity (denoted by *) also is striped, and it shifts from drive to drive. A parity block (*) contains a representation of the data from the other blocks in the same stripe. For example, the parity block in the first stripe contains data representation of blocks 1 and 2.
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If a physical drive fails in the array, the ServeRAID controller switches
read and write requests to the remaining functional drive in the RAID level-5
array, which is a hot-spare drive. |
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See also
Understanding
RAID technology
Understanding
stripe-unit size
Selecting a
RAID level
RAID level-0
RAID level-1
RAID level-1
Enhanced
RAID level-5
Enhanced
RAID level-x0