RAID Levels Overview
RAID systems combine multiple disks into a single unit to achieve greater performance and increased fault tolerance.
Various RAID levels balance the advantages by combining sets of operations, including:
- Distributing Data Across Multiple Disks, or "Striping".
- Copying Data on a Second Drive, or "Mirroring".
- Incorporating Parity Blocks to Recover Threatened Data.
- Coordination of Reading/Writing Tasks by Disk Array Controllers.
RAID 0 systems increase read/write speeds by using striped sets to record fragmented data across several disks simultaneously. Because RAID 0 arrays don’t include data redundancy, disk failure can still result in lost files. For greater fault tolerance, RAID 1 is the simplest option. These systems safeguard their contents with disk mirroring capabilities, creating total redundancy for effective data protection.
RAID 5 achieves fast write speeds with striped sets while protecting data by distributing parity across several drives. Of all the options, RAID 5 is the most popular for use with web servers. RAID 6 arrays are similar to RAID 5, but an extra parity block provides stability even if two drives fail.
Offering the greatest fault tolerance, RAID 10 combines the benefits of striping and mirroring to maximize performance and protection from failed components. RAID 0+1 arrays invert the RAID 10 configuration with mirrored sets of striped arrays.
To determine the performance data of a given RAID array, enter the parameters into the fields above and click "calculate".