Raid Conversion

[lopix]

Have a weird question. Is it possible to set up a 2-drive raid 0 array, write data to it, then add another 2 drives at a later date, set up as another raid 0 array, and mirror the first array onto the 2nd to create a 0+1 configuration? Without losing the original data! And, can this be done with an onboard controller such as Promise or Highpoint?

[Stan]

Hi,

In your case, you should be able to convert (morph) the RAID0 into a RAID0,1 array. I don't think it is possible to morph into RAID10 - which is different.
RAID0,1 is a mirrored array whose segments are striped (or RAID0)
RAID10 is a striped array whose segments are mirrored (or RAID1).

In your case, your data is already on a RAID0 array. RAID0,1 would be the "logical" morphing.

There are different kinds or morphing: from RAID10 to RAID5, RAID5 to RAID1, ...
Morphing depends on the controller and mostly on the management software that comes with the RAID controller.

I used to work on DELL PE servers and adding a disk to a RAID5 array was easy thanks to the very good disk management utility.
I don't know it Promise or Highpoint controllers come with such a utility.

So, to answer your question: this is what I would do:
- keep the existing RAID0 array
- setup a 2nd RAID0 array
- use software RAID to do the mirroring
Unfortunately, soft RAID in only available with Windows Server.

Hope that helped a bit...

Stan

[lopix]

Thanks Stan, just knowing that the theory is sound is good. To tell the truth, I really don't see any reason why it should not be possible. I guess the real question is, using an onboard controller, can you set up one array, then another at a later date. If so, there should be no reason why I can't set up the first 0 array, then the second. Then the question is simply the mirroring. Since both controllers I mentioned support 0, 1 and 0+1, there should be no logical reason why it is not possible, right?

[Mntsnow]

Correct. You should be able too.

[lopix]

I guess there is no real way to know other than try it. If I backup the data on the original array, then I am safe even if it does not work. I wish someone had done this and could tell me for sure.

[Mntsnow]

Sorry but I havent but Yes ALWAYS backup prior to doing system config changes :)

Good luck