Summary
of RAID Levels
RAID
Level |
Description |
Minimum
Number of Drives Required |
Maximum
Number of Drives Supported |
Data |
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 (if controller supports 2 channels) 8 |
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 storage 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. |