Degraded RAID

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Degraded RAID

We have an earlier-generation Xserve RAID, set up to RAID 5, where a drive has failed, and therefore the status is Degraded. The failed drive in question was a 250Gb Hitachi, which seem to be no longer available. Instead I have ordered a 250 Gb WD Caviar Blue PATA.
Should it be as easy as pulling out the dead drive, popping in the new drive and putting it back in position in the RAID? Will the RAID repair itself, including formatting the new drive (assuming the WD is good)?

Mac OS X (10.5.7)

Posted on Jun 24, 2009 11:24 AM

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Answer 1

Jun 24, 2009 11:41 AM in response to JD Maass

Assuming the new drive talks with the RAID SMART controller and isn't any smaller than the previous drives then this should work.

Depending on the state of the drive you might have to go into RAID Admin and mark the drive as "Available for Use" but other than that it should rebuild.

=Tod

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Answer 2

JD Maass Author

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Jun 26, 2009 2:31 PM in response to Tod Kuykendall

OK... popped it in and it seems to read it OK. The light turned green and it is showing up in RAID Admin as a spare, sees all its details, etc. I don't see where I would mark it as "Available for Use"... the array still shows up as "Degraded".
Do I have to initiate the rebuild in some way?

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Answer 3

JD Maass Author

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Jun 26, 2009 2:42 PM in response to JD Maass

Arrg... I think I see where to mark it as "Available"... under Utilities, right? But it is grayed out.
I think the problem might be that the new drive, even though it is a 250Gb drive like the old one, it's being seen as 232.88 Gb where the old one was 233.76 Gb! Bogus! So presumably I'll have to order another, even larger drive.
Could this be the issue?

Message was edited by: JD Maass

Message was edited by: JD Maass

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Answer 4

Jun 26, 2009 3:36 PM in response to JD Maass

If it shows up as a few bytes smaller it won't use it in a RAID with larger drives - that's why I mentioned it in my first post. You can use a larger drive but not a smaller one. The actual size reported can vary by manufacturer or even by drive line.

Sorry,

=Tod

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Answer 5

JD Maass Author

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Jun 29, 2009 5:05 AM in response to Tod Kuykendall

Uh oh... now I'm in trouble, I think. This morning the main volume on this RAID was doing a funny thing where you try to open it and it does like a Finder reset without ever opening. Restarting the RAID, that volume now does not mount. Also, this volume backs up to another drive, and it is doing the same thing where clicking on the main folder to open it causes a similar Finder reset and disappearance. I think I may be f*ed.

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Answer 6

JD Maass Author

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Jun 30, 2009 4:47 AM in response to Tod Kuykendall

OK... a progress report. Thanks for all the help so far, Tod.
I got a larger drive to replace the failed drive, got it in and the array rebuilt itself. The greyed-out options in my RAID Admin Utilities menu turned out to be due to an uninstalled firmware upgrade... it has now been installed and I seem to have all my options.
However, the rebuilt array... although it says it is all good in RAID Admin, the volumes on it will not mount. Dist Utility says "Filesystem verify or repair failed". Am I doomed? Have I lost all the data? I've trying a "Verify Parity" in RAID Admin Utilities now, but every time you do anything in here is takes many hours. Will the "Rebuild Parity" option un Utilities do anything different, or was this what it was doing automatically when the new drive went in? Is there any other software I should try to get the volumes on here back? Am I asking too many questions?

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Answer 7

Jul 1, 2009 6:50 AM in response to JD Maass

I think you have two separate things going on here - assuming you didn't lose a second drive in the RAID5 before you added the new drive the RAID should be okay.

Did the file corruption occur before or after the rebuild took place? If it's after then perhaps the RAID rebuild was unsuccessful. I know this is a possibility but I've never heard of it happening with an Xserve RAID specifically.

You should try rebuilding the RAID parity and yes, it will take quite a while. If that doesn't work there are more tools you can try - Disk Warrior is one that will recreate directories - and while they are really RAID certified kinds of tools what could it hurt at this point?

Good luck,
=Tod

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Answer 8

Bono11

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Sep 3, 2009 7:12 AM in response to Tod Kuykendall

Hi Tod,
Sorry to reply to a different post, i'm unsure how to privately email, but we are having a RAID issue it hought you might be able to help with.

We currently have an xServe Raid in RAID 50 config with 14 drives (7 each side). One drive went down and we took it out and ordered the part (now running 7 on left and 6 on right) and the RAID data was fine. While trying to configure another RAID for temp usage, I accidentally (here's where everyone shurgs) reformatted the original RAID with all our data (non destructively, not writing anything over it) but of course, i lost the original volume which created the single RAID from across the 14 discs. Help. Do you know of any tools that can find the old volume and restore it for us (no, we hadn't backed up the RAID volume). Right now we're using Virtual Lab to try and restore. But any ideas or help would be MUCH appreciated.

Thanks.

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