What is RAID 5 (striping with parity)?
RAID 5 (striping with parity) A RAID 5 array contains three or more hard drives where the data is divided into manageable blocks called strips. Parity is a mathematical method for recreating data that was lost from a single drive, which increases fault-tolerance. The data and parity are striped across all the hard drives in the array. The parity is striped in a rotating sequence to reduce bottlenecks associated with the parity calculations. The capacity of a RAID 5 array is the size of the smallest drive multiplied by one less than the number of drives in the array. The equivalent of only a single hard drive is used to store the parity information, allowing for fault-tolerance with less than the 50% capacity reduction of RAID 1. For example, three 400 GB hard drives in a RAID 5 array will appear as a single 800 GB hard drive to the operating system. The primary benefits of RAID 5 include capacity and data protection. Because parity is used for data protection, up to 75% of the total dr