User`s guide

Appendix D
RAID Quick Reference
This appendix provides quick-reference information about the RAID levels
supported by your iSCSI Storage Appliance.
Comparing RAID Levels
Use this table to select the RAID levels that are most appropriate for the pools on
your IP SAN, based on the number of available disk drives and your requirements
for performance and reliability. Only the RAID levels supported by your iSCSI
Storage Appliance are listed.
Disk drive usage, read performance, and write performance depend on the number
of drives in the pool. In general, the more drives, the better the performance. More
information about each RAID level is available in the Glossary on page 213.
Note None of the RAID levels listed include a built-in hot spare.
Selecting a RAID Level by Size of Pool
Use this table to select a RAID level based on the number of disk drives in your
pool.
RAID
Level
Redundancy
Disk
Drive
Usage
Read
Performance
Write
Performance
Minimum
Disk Drives
RAID 0 No
✱ ✱ ✱ ✱ ✱ ✱
2
RAID 1 Yes 100%
✱ ✱ ✱ ✱
2
RAID 10 Yes 50%
✱ ✱ ✱ ✱
4
RAID 5 Yes 50%
✱ ✱ ✱ ✱
3
RAID 6 Yes 67% – 94%
✱ ✱ ✱
4
Spanned
Volume
No 50-88%
✱✱
2
Number of Disk Drives in Pool Possible RAID Levels
One Simple volume