[CentOS] Centos and Software RAID

Fri May 26 21:56:00 UTC 2006
Barry L. Kline <blkline at attglobal.net>

Erick Perez wrote:
> I purchased an Intel D945GNT motherboard and it comes in the BIOS with
> an option to create a RAID 0 or RAID 1 volumes using my existing two
> SATA disks. However when installing Centos 4.3 x86_64 I see the the
> installer recognices the two drives and does not "see" the RAID 0.
> Is that ok?
> Should I disable the RAID in the BIOS and then go for a LVM+RAID 0
> setup in the installer ?
> Since it will be a server machine I want to gain the performance of
> RAID 0 without too much complications (i will use ext3 instead of
> ReiseFS)

Hi Erick.

It's doubtful that your on-board RAID controller is going to work with
Linux.  Most of the on-board controllers are really nothing more than
two SATA channels with the driver (for Windows) providing the RAID
functionality.  Thus, you're really not gaining hardware RAID, in spite
of what you are led to believe by the BIOS options.  That's why Linux is
reporting it as two drives.

You have two choices:  1) Buy a hardware RAID controller (my choice
being the 3ware brand), or 2) use software RAID.  Since that's what
you'd be getting anyways if you were using this board with Windows and
the appropriate driver, you're not losing anything.

FWIW I've had no problems whatsoever when using software RAID. I use it
on many of my servers.