I'm in the planning stages of setting up a file server and am considering using RAID.
My concern is that my drive sizes are mixed. I have two 500GB SATA drives, a 320GB IDE and a 250GB IDE. I would like to set these up so that the maximum amount of disk space is usable, but still be able to recover from any one drive failing. I would also like to be able to add drives of any size as easily as possible. Is it possible to split each disk into a bunch of 10GB partitions, giving me 157 partitions in total, and specifying that I want to have 50 partitions worth of parity info so that if any 50 partitions go bad (ie: one of the 500GB disks) the RAID can recover? Adding/replacing would be simple if I can change the amount of parity info to keep, but I don't know if this is actually possible. It looks as though spares need to be explicitly given so, if a disk with lots of spares goes down, it's not going to work. Another option I see is if I create 4x 250GB partitions (one on each drive) in one RAID5 array, 3x 70GB partitions (on the 3 larger drives) in another RAID5 array, and two 120GB in a RAID1 array. The RAID1 array reduces my total available disk space a bit, which is less than ideal and adding/replacing disks would be more of a headache. I remember reading something about using LVM and RAID to achieve this, but everything I've found has been for identical drives. Any suggestions?
