Users Guide

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.

Table 1. RAID Level and Concatenation Performance Comparison

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