Comparing RAID Level And Concatenation Performance
The following
table compares the performance characteristics associated with the
more common RAID levels. This table provides general guidelines for
choosing a RAID level. Evaluate your specific environment requirements
before choosing a RAID level.
NOTE: The following table
does not show all supported RAID levels in Storage Management. For
information on all supported RAID levels in Storage Management, see Choosing
RAID Levels And Concatenation.
RAID Level | Data Availability | Read Performance | Write Performance | Rebuild Performance | Minimum Disks Required | Suggested Uses |
Concatenation | No gain | No gain | No gain | N/A | 1 or 2 depending on the controller | More cost efficient than redundant RAID levels. Use for noncritical data. |
RAID 0 | None | Very Good | Very Good | N/A | N | Noncritical data. |
RAID 1 | Excellent | Very Good | Good | Good | 2N (N = 1) | Small databases, database logs, and critical information. |
RAID 5 | Good | Sequential reads: good. Transactional reads: Very good | Fair, unless using writeback cache | Fair | N + 1 (N = at least two disks) | Databases and other read intensive transactional uses. |
RAID 10 | Excellent | Very Good | Fair | Good | 2N x X | Data intensive environments (large records). |
RAID 50 | Good | Very Good | Fair | Fair | N + 2 (N = at least 4) | Medium sized transactional or data intensive uses. |
RAID 6 | Excellent | Sequential reads: good. Transactional reads: Very good | Fair, unless using writeback cache | Poor | N + 2 (N = at least two disks) | Critical information. Databases and other read intensive transactional uses. |
RAID 60 | Excellent | Very Good | Fair | Poor | X x (N + 2) (N = at least 2) | Critical information. Medium sized transactional or data intensive uses. |
N = Number of physical disks X = Number of RAID sets |