Summary
of RAID Levels
RAID Level |
Description
|
Minimum Number of
Drives Required |
Maximum Number of
Drives Supported |
Data Reliability
|
Data |
0 |
Striping of data across multiple drives in an array. This is a high performance solution, however there is no data protection. |
2 |
4 |
No data protection. |
Very High |
1 |
Also known as mirroring. Mirroring refers to the 100% duplication of data from one disk to another. This is a high availability solution, but due to the 100% duplication, it is also a costly solution. |
2 |
2 |
Highest reliability; much higher reliability than a single drive (no RAID). |
Reads are the same as a single drive. |
0/1 |
Mirrored striping need 4 disks. |
4 |
4 |
Same reliability as RAID 1; higher reliability than a single drive or RAID 0. |
Reads are similar to RAID 0. Writes are about two times of RAID 0. |