Thread: Hard Disk RAID

Originally Posted by bunuvercem

first of all, you need the same HD's for raid. ;) secondly, i think, you got the raid idea kinda wrong. as far as i know, raid is not the solution for this.

Actually, you don't need the same drives for a RAID array. You have to decide what kind of array you want to build though. If you go RAID 0 - for max performance - with different sized hard drives, you will only 'double' the size of your smallest drive (ie 100GB+250GB= 200GB. If you choose RAID 1 (or mirrored) for redundancy, only the smallest HD size would be mirrored. (ie. if you had a 250GB + 500GB, your mirror size would be 250GB).

Anyway, it sounds like you want to do a JBOD, which is technically not a RAID array. "Just a Bunch Of disks" have all disks keep their various size but look like one drive to your OS.

Wiki puts it this way:

The usage is contentious; in careful usage, JBOD refers to the first (independent disks), as there is no other term to refer to this, while concatenation is referred to by unambiguous terms such as SPAN or BIG.

Concatenation is sometimes used to turn several odd-sized drives into one larger useful drive, which cannot be done with RAID 0. For example, one could combine 3 GB, 15 GB, 5.5 GB, and 12 GB drives into a logical drive at 35.5 GB, which is often more useful than the individual drives separately.

Then again, I could be missing what you are trying to say. (Now that I re-read your message, would you might be thinking about an expandable RAID 5? )