RAID (redundant array of independent disks) is the dominant technology in high-performance and high-availability storage systems, providing a number of choices and compromises for optimizing performance, price/performance and availability for particular applications. We can measure the performance impact of different levels of RAID in various application environments using standard benchmarks. This white paper describes the performance differences among the three most popular RAID levels -- RAID-1, RAID-5 and RAID-A (also called RAID-0+1) -- and helps you determine when to use one level over another. (June 1999)

RAID-1 = mirroring
RAID-5 = striping with parity
RAID-A = striping and mirroring