RAID 5

RAID 5 protects data using parity (denoted by Px,y in the figure). Parity data is calculated by summing (XOR) the data from each drive within the stripe. The strips of parity data are distributed evenly over every physical drive within the logical drive. When a physical drive fails, data that was on the failed drive can be recovered from the remaining parity data and user data on the other drives in the array. The usable capacity is C x (n - 1) where C is the drive capacity with n drives in the array. A minimum of three drives is required.

RAID 5

This method has the following benefits:

  • It is useful when usable capacity, write performance, and data protection are equally important.

  • It has the highest usable capacity of any fault-tolerant configuration.

  • Data is not lost if one physical drive fails.