Raid 0 Problem - Would this work as a fix?

Hi, can a Raid 0 be run off of three hard drives or must it be an even number?

I've always heard that it can be any number (even or odd) for a raid 0. However, in the manual for my GA-X48-DQ6 it says: "A raid 0 or raid 1 configuration requires at least two hard drives. If more then two hard drives are to be used, the total number of the hard drives must be an even number". Is that correct? I already picked up three of the new 640 GB WD drives and if this is true, I have a problem. Maybe different when using a hardware raid card then it would be when using this motherboard's software raid (in this case it would be software)? It is controlled with the Intel ICH9R raid controller.

If the Intel ICH9R controller does indeed need even number of drives, and supports a max partition of 2TB, here is what I could do.

1. As of now, the three WD 640GB drives I have come to 1,788GB (after formating). I could buy a forth and partition in it enough to equal 2,000GB even. And then use the rest for the OS and what now. However, first, could this be done? And would doing this affect the overall read/write speeds of the raid0? After all, three drives would be running at their full size and the forth would be using like 1/4 of it.

2. Return the three WD 640GB drives and buy four 500GB.

Any thoughts?

RAID0 can be run with any number of drives.

Keep in mind as more drives are used in a RAID0 array, 1) the performance increases, and 2) the failure rate also increases, 3) it's best if the drives are all same size and specs and, 4) the OS and controller can/might limit the size of the array.

If you create back-ups of your data and/or create and image of the drive, then a drive failing is not too big an issue.

Not sure what to say about how to divy up the space. Me personally, I'd get smaller (maybe 2 or 3 80GB drives) than 640GB drives and create a RAID0 array for the OS then use the 3-640GB drives in a RAID5 on a separate hardware controller for storage; but that's just me.

Either way, good luck!

What motherboard do you have? Limiting the arrays to only an even number of drives is not something spec'ed by Intel, well at least not according to the ICH9R docs on the Intel website. Unless the mobo maker of your board changed the ICH9R BIOS or implemented a different config, there is no reason you can't use 3 drives and the Matrix RAID feature to create your multiple arrays on the ICH9R with the 3-640GB drives.

Yes...you can do just that with the Intel Matrix RAID and the ICH9R.

Why do you need so much fast access?, if you just want a large data dump then treat them as three seperate drives, failure then becomes less critical. You mentioned that you could put the OS on some of the remaining space so you weren't planning on using it for the space on a system drive.

I'm running Raid0 and Raid1 on the same 2 disks and it is very fast (WD500RE2's), however I'm getting minor corruptions on the Raid0 and the Raid1 on rare occassions. The Raid1 will rebuild itself quite happily, the Raid0 just makes me touch cloth whenever I start her up...

So for a data tank, either go raid5, or JBOD, from a speed point of view it is unlikley you'll notice the difference if it is for media (you only need what the film is asking for, any faster is a waste).

Thats my 2p, really really question why you are needing that much in Raid0.

so its temp storage? security is not an issue, I assume that you have other media to back up to, and that this is just working space or scratch space?

I've seen some people round here trying to setup raid0 arrays simply for storage and torrenting, its good to see them being put to a use that needs the speed in this case.

Bear in mind that the failure rate of each drive stays the same. The failure rate of the RAID array as a whole does increase, because if any one drive crashes, the whole array crashes. But that doesnt mean any single drive suddenly becomes less reliable as soon as its in a raid array (unless its in close proximity to other drives and not adequately cooled).