RAID5 Disk Recovery

April 21, 2007 5:27 PM

I need some help and some hand-holding with hard drive recovery on a failed main drive in a Windows Server 2003 RAID 5 array.

Well, I think I've gone and done it this time. I have (had) four drives involved in a RAID5 array in a Windows Server 2003 installation -- three 120GB drives in the actual array, and an 20GB drive as the system drive. A couple of months ago, the motherboard went and died on me (thought RAID5 was pretty safe, but didn't think of that one). Obviously, I don't have backups. I've built a new box with the intention of offloading the data to a nice new 1TB SATA RAID10 array, but during the migration of the old array to the new box, something happened -- something bad. The three data disks are recognized, but the 20GB system disk appears to be blank, which means that my array... isn't there. (You've never heard the word 'fuck' so many times, believe me.)

Recovery programs show that the filesystem seems to be more or less intact (it shows plenty of data on the drive), but obviously Windows can't see it, which makes me think that the problem is just that either the MBR or the partition table has been corrupted or overwritten. Those same utilities tell me that they can recover my files, but something tells me that I need to have the entire drive recovered intact in order to have my array be recognized by the new OS, so that's what I'm looking for -- instructions on how to restore that drive completely so that I can use it as the fourth drive in the array.

I'm reasonably computer literate, write code/manage programmers for a living, and maintain several boxes of various types at home, so I should be able to follow advanced instruction if necessary. But I just don't want to take any chances here. This array contains around 10 years of my life -- downloaded and purchased music, mixes that I've done (I'm a DJ at night), financial information, pictures, and other personal records. While I won't exactly die without the data, it sure would be painful to lose it, so I don't want to take any chances. I have a feeling that I only have one shot at this. I'm hoping someone here has had some experience with this situation and can lend their expertise.

(Oh yeah, and if you can get me outta this one, I PROMISE to back everything up... multiple times.)

posted by Oops to computers & internet (7 comments total)

OK, let me start by saying, RAID IS NOT A BACKUP!!!!!

:-)

That said, now, can you tell us if the raid5 array was a hardware array or a software array ?

If it's a hardware array, you may be able to install a new OS (or use a Ultimate windows boot cd) and recover the data from it. (the odds vary depending on the hardware involved, though, so I am not making any promises.)

If it's a software array, then in my experience, you need to recover the original OS. I'd start by running the windows recovery tool and doing a chkdsk.

I will admit I don't have very much experience trying to recover failed arrays. The first sentence in this post explains why. :-) But if you can tell us the answer to the first question, we might be able to help more.
posted by Pogo_Fuzzybutt at 6:07 PM on April 21, 2007

This is worth a shot. You need to build a duplicate array, though:

http://www.runtime.org/raid.htm
posted by disclaimer at 6:28 PM on April 21, 2007

Presumably you were using Server 2003's software striping..

With NT 4 you were instructed to make an array definition disk (a floppy), for just this sort of problem. With the array definition disk you could migrate the array to any other system with no problems. I read that the array definition disk wasn't strictly necessary, but I can't find it..

More modern versions of Windows software RAID-5 don't seem to require the array definition disk at all.. I expect that you can just drop your 3 120GB drives into any windows system that supports RAID-5 (hacked XP, or Server 2003, etc.), and Windows will find your array.
posted by Chuckles at 9:04 PM on April 21, 2007 [2 favorites]

Before you do anything, back up the disks you've got.
posted by BrotherCaine at 11:32 PM on April 21, 2007

Chuckles-

Thanks for the links! If this were my question, you'd get a best answer.

I've wondered for a long time now about transferring my server RAID to other hardware, and even about simply dropping in a new drive for a failed one.

Your links explained things that not even the RAID section of my Server 2003 Inside Out book addressed. This is critical information. Thank you.
posted by SlyBevel at 11:13 AM on April 22, 2007

Chuckles, you're right -- I am (was) using Server 2003's striping. I thought that I would be fine with just the three main drives and wouldn't need the fourth drive, but Windows won't recognize the array without the system drive. Windows tells me that I can import the foreign array, but because it's incomplete I may lose data.

Is there a way that I can find out what I'll lose? Or do I just have to chance it? The thought of importing and losing the whole thing makes me want to chew my fingers off.
posted by Oops at 3:00 PM on April 23, 2007

Sorry, didn't notice the new post until recently..

Your drive configuration was 3x 120GB in Windows RAID 5, and one regular 20GB system drive?

You should be able to drop the three drives in a new system with no problem.. I just changed my motherboard over the weekend, and once I rehacked XP for RAID 5 support, the array was fine.

I really don't know what you should do at this point.. I suspect that you won't actually lose any data after importing it, but I don't have any direct experience. So, it really depends on how critical the data is. You could, for example, buy a ~400GB drive, and create block by block drive images of each of the RAIDed drives before you do anything. Of course you can't really know if the images are "right" without testing your procedure somehow first.. You really need somebody who has seen that exact message before..
posted by Chuckles at 5:39 PM on April 30, 2007