Raid 5 rebuild shows unallocated?

  robotnik 18:55 20 Nov 07
Locked

Any help on this would be VERY much appreciated!

Today, using server 2003 R2, one of the discs in a raid 5 configuration went down.

This disc (one of 4 320Gb WD sata hdd's) was replaced with a new hdd drive and the array was then rebuilt with the nvidia utilty that came with the asus (Asus M2N32 WS PRO) motherboard.

When the rebuild was complete the array didn't show up in the "my computer" section and has disappeared, and it now shows as unallocated in the disc manager.

Is there a way to recover the data on the array? The searches I've done only seem to throw up the usual professional recovery services.

If you need any more info let me know :)

Thanks very much for looking.

  I am Spartacus 20:17 20 Nov 07

Any use? click here never heard of it.

  robotnik 20:53 20 Nov 07

Thanks spartacus.

I was hoping there would be an easier solution to be honest. There doesn't seem to be too much info out there on it. Especially as RAID is supposed to guard against this sort of thing...

Any more suggestions? :-)

  I am Spartacus 21:05 20 Nov 07

Have you tried removing the new disk, trying another rebuild, formatting the new disk separately and then trying again.

A consumer board like that isn't exactly resilient in the mission critical sense.

  robotnik 21:39 20 Nov 07

Not tried another rebuld, just the one. After it came up like that, thought it wise to try another avenue after it came up as showing unallocated.

  UncleP 00:47 21 Nov 07

I haven't any experience with RAID5 arrays, but have rebuilt RAID1s on a couple of occasions, so here are some comments which might (or might not!) be helpful.

First, you say that the re-build you tried was complete: did it take the time expected ie several hours for 320Gb disks, and did you get a terminating message eg 're-build successful' or 're-build complete'?

Second, the nVRaid re-build utility supplied originally with my machine did not work; this was obvious as it took only a minute or so to complete, and the array was still registered as 'degraded'. I got an up-dated version from the motherboard manufacturer which did function correctly, so its worth checking with them to see if an up-grade exists.

Third, there is a detailed manual on the web, called something like 'The nVRaid users guide v20' which covers all aspects of setting up RAID arrays using the nVRaid manager. From memory, it contains instructions on initialising an array - which might be what you need to do, although I would have thought that it would be unnecessary for a re-built array.

Fourth, the place to look for information on HDs, arrays etc is not in My Computer, which will only show fully functioning, assigned and initialised disks or arrays, but on the RHS of the Disk Management page. If the array has been re-built, it should appear as a single disk designated 'DiskN' (where N is an integer from 0 upwards). If not the component disks will appear separately. If they don't appear at all, they are either non-functional or not connected, one way or another. For each entry, status information is given in the DiskN panel or at the top of this page. This will tell you what the condition of the disk is; in general it may then be brought on-line using the utilities available on that page.

That should keep you busy for an hour or so! If you find the array in the list, but still need some assistance, post the status diagnostics here and I'll see if they ring any bells. One warning: one of utilities on the Disk Management page may tell you that the disk (or array) is unformatted, and offers to format it for you. Don't! - your files may still be there and recoverable. Re-formatting is a last resort when all hope has gone, and you're nowhere near that position.

Good luck!

  robotnik 07:58 21 Nov 07

Thanks very much for your detailed input!

I shall check all that today and hopefully get back to normal.

And of course report what happens either way.

Fingers crossed!

  UncleP 11:17 21 Nov 07

I've just checked the RAID manager manual referred to in the third item above, and found that it does not include RAID5 arrays. There is some information on initialising etc of other simple arrays which might be worth a brief read, however. But I suggest you leave this item until last, as it might prove unnecessary.

  robotnik 19:41 21 Nov 07

Thanks for everything UncleP.

I tried all that and eventually thought it an idea to try some recovery software as it seemed the only avenue left.

The long and the short of it that the software I tried managed to recover 39% of the files.

For reference they were getdataback NTFS and R-Studio. Both came up with similar results so it's safe to assume that that's what's recoverable. So I'll buy the full version of one and pull the files off before deciding if it's worth trying another.

Thanks again for everything, you have been a great help, and I hope I can return the favour one day :-)

  UncleP 00:08 22 Nov 07

Better than nothing, I guess, but a little disappointing since the whole point of RAID systems is to provide some insurance against disk failure. Anyrate, I'm pleased to have been of some assistance.

  robotnik 12:36 22 Nov 07

Exactly, that is the point. I guess everything's fallable...

That's probably another reason why there doesn't seem to be much documentation around on how to deal with this sort of thing, because its so rare...

Anyway, once again thanks very much!

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