Re: RAID

[lsorense@csclub.uwaterloo.ca (Lennart Sorensen)]

On Tue, Nov 08, 2005 at 12:14:52PM -0800, lordSauron wrote:
> Hi, I was just doing some information gathering for a potential
> upgrade I want to perform.
> 
> I have a ECS Elitegroup nForce 3-A motherboard, which has built-in
> RAID 0/1/0+1 support.  I want to get a 80 Gb SATA150 drive, but if I
> can get RAID to work with linux, I'd love to pay more but get two 40
> Gb SATA150 drives, and RAID 0 them together.  *However,* when I tried
> this with a ATA 27 Gb drive and a IDE 14.7 Gb drive (a IBM Deskstar
> and a Segate brand drive respectively) and then tried it with the
> amd64 installer (which supported kernel ver. 2.6.x-11, the x being
> holes in my memory) it didn't work (or at least I couldn't make it
> work, but I'm still not that great at installing so it's totally
> possible I just majorly screwed up and did something stupid along the
> line...).  I think it'd work with the newer kernels (>= -12) b/c with
> the -11 my m-board integrated audio and LAN didn't work, but now they
> do... so I think that it's just that the -11 kernel didn't yet have
> the device drivers for these components, and now that these things
> work, the RAID should work too, right?  I just wanted to see if anyone
> knew the status of this...
> 
> Thanks for any info you can give me!

Use software raid in linux.  The installer can allow yo to set it up.

No desktop motherboard has hardware raid onboard.  Many have fake raid
however which is simply the bios pretending to be raid until the driver
(usually proprietary) takes over doing raid.  It is all software, and
usually not as fast or efficient as what linux can do in software.

Now why would you buy 40G drives when they cost (at least around here)
the same as 80G drives.  2 x 40G would cost twice the price of a single
80G.  Buying a pair of 160 or 200G drives would make much more sense.
Also larger drives are denser and hence faster than smaller drives, so
you may actually get less performance striping two smaller drives, and
the reliability goes way down since you have two points of failure
instead of one.  Insane setup really.

Len Sorensen