We have a server with 2 500GB hard drives which are currently mirrored (RAID 1), but we're running out of space now. So, we have one more bay available, so my question is: if we buy 1 TB hard drive and configure them in nested RAID levels with those 2 500GB drives in RAID 0 (= 1 TB) and the new 1 TB drive in a one drive RAID 0 (= 1 TB), and then mirror those 2 RAID sets with a RAID 1... would I get 1 mirrored TB at the end?


  • As Techie007 already said: You can if your RAID controller supports it. Do keep in mind that, most likely, you can't migrate your current setup to the new one, while keeping the data intact. You will have to backup. Reconfigure the RAID and then restore. – Tonny Oct 31 '14 at 20:43

Yes in general you can do it, but it depends on the specific RAID controller's abilities.

In the end you wouldn't make a RAID0 to add that as one side of a RAID1, instead you'd use a span to create a single volume by concatenating the two 500GB drives together.

Exactly how you do this, again depends on the specific RAID controller being used.

  • "You can't have a RAID containing only a single drive." - pedantically, you can. I've done so before, with Linux software RAID. It's generally not a good idea (pointless at best, counterproductive at worst) but it is possible. – ChrisInEdmonton Oct 31 '14 at 19:48
  • 1
    True enough... you can have only one drive in a two drive RAID as well, if one drive fails I guess. :) But then it's technically not a RAID, at least not a functioning RAID. Maybe I'll rephrase to "true, functioning RAID", or just axe the statement. ;) – Ƭᴇcʜιᴇ007 Oct 31 '14 at 20:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.