Can I set up a raid array where I have multiple small drives that back up to one large drive?

Question

I want to know if I can set up a RAID of 150 GB velociraptors for performance and then make it so where they automatically back up to a larger say 2TB western digital caviar black drive?

Let me know if this is possible and what drives I should get and what RAID controller I should buy!

Answer 1

As aked this does not make sense:

Can Iset up a RAID of 150 GB velociraptors for performance.

Yes. Trivially easy. And it can be done both in software or with hardware. For max performance you probaly want stripe/RAID1.

(AND RAID 0, RAID 1 and combination like RAID10 work fine without huge CPU loads.)

and then make it so where they automatically back up to a larger say 2TB western digital caviar black drive?

Uhm no. Or no and yes.

No because RAID is not a backup.

You can however do the following:
First create an array of 10x 150GiB raptors (fast but insane to use that many drives that way).
Then create a mirror of the fast array and the big disk.

This will not backup. This will write a copy of the data to both the fast disks and the backup disk. Thus coming close to what I guess you want to archive.

However depending on your actualy implementation the setup may very well wait until data has been written to both the fast array and the big disk, thus making it as slow as the big disk. And reads might be equally distributed (meaning half the reads may come from the slow disk).

Note that you can still create a very nice fast array with the Raptops. E.g. in a stripe, or a RAID10. And you can backup (as in, actual backup tools) the data. Just do not try to use RAID as backup. Instead rsync daily.

Answer 2

I think you will want to back up the files, not the drives, so it doesn't really matter how your physical drives are arranged. Set up your backup job to copy the files off of the filesystem (which is a few levels of abstraction above the physical drive/raid arrangement) and you should be all set.

Answer 3

Yes, it is possible. Some LG nas servers allow ya to automatically back up stuff off of that to an external usb drive. Well, any raid controller that supports 1 and 5 would do.