0 | Striping, where data is simply striped across multiple disks to make one larger logical file system; no parity information is used; one dead disk takes out the whole array |
1 | Mirroring, where one disk is duplicated onto another disk; if either disk fails, the other disk has all the data (no data is lost) |
2 | Parity (proprietary), special case. Patented by Thinking Machines, Inc. Hamming code disk array which consists of data drives and multiple parity drives. |
3 | Striping with parity, where one disk in an n-way stripe is reserved for parity information (also known as byte striping) |
4 | Striping with parity, where one disk in an n-way stripe is reserved for parity information, using a variable striping unit size (also known as segment striping) |
5 | Striping with parity, where information (including both data and parity) is striped across all disks in an n-way stripe |
S | Striping with parity (proprietary), where information (including both data and parity) is striped across all disks in an n-way stripe; proprietary to EMC Corp. (no longer in use) |
6 | Segment striping with multiple parity, an improvement on RAID 5 by having multiple parity drives, allowing for multiple disk failures with no data loss |
7 | Striping with parity (proprietary), a method patented by Storage Computer Corp. where data is striped across multiple drives with one or more parity drives (an unofficial RAID level) |