RAID 5 vs RAID 6: Which one is best for SSDs?

Originally posted on https://www.virtualizationhowto.com by Brandon Lee on September 29th.

Using a single “hard drive” is bad when it comes to the availability of your data. If you lose that single hard drive and have no backup, you have no means to recover it. Combining multiple disks forms a “raid array” to achieve specific benefits, such as resiliency against failures. RAID, or Redundant Array of Independent Disks, is designed to increase storage performance and data security, allowing you to have a failure of a disk and still have your data intact. Two such configurations often compared are RAID 5 vs RAID 6. What are the differences between these two RAID levels, and which one should you use?

Parity Data — What is it?

Understanding Parity data is essential to understand the differences between RAID 5 and RAID 6. Parity information ensures data protection and allows the recovery of lost data if a disk fails in your data storage configuration. The system computes and stores this parity data across the disks in the RAID array.

In the context of RAID arrays, parity data provides error correction. It’s a mathematical mechanism that provides redundancy to help recover data during a drive failure. The primary principle behind parity is using the values of bits across multiple…