SetupRecommandattions:RAID

Raid

We recommend HarwareRaid, RAID 1 or RAID 5, to build disk failure tolerant servers. Be careful not to buy servers with FakeRAID. Vendors are advertising their servers as RAID servers, but make sure that it is true HarwareRAID, or else it could be preferable to buy your servers with no RAID at all, and use Linux Software Raid instead.

FakeRaid

FakeRAID is the equivalent of not having RAID at all, since it's the BIOS that emulates the RAID and thus, the CPU ends up doing all the job.

Under Linux, if you have a server with FakeRAID/BiosRAID, then you should disable it in the BIOS and use Linux SoftwareRaid.

A list of FakeRAID hardware devices/controllers can be found here http://linuxmafia.com/faq/Hardware/sata.html

Linux SoftwareRaid

For servers without RAID or with FakeRAID, SoftwareRaid should be used.

SoftwareRaid is better than FakeRAID because it is well supported under Linux. The kernel supports it natively, and mdadm can be used to manage and to view the status of the RAID devices.

Please see your Linux distribution documentation on how to setup SoftwareRaid.