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I have a dedicated server with two identical hard drives, which ran in a raid array, mirrored until yesterday, when the datacenter had a power failure and corrupted one of the discs. I figured if I 'break' the mirror (not 'remove'), I would be able to get TWO identical copies of the data, one on the bad drive and one on the good drive. But alas, after performing the 'break mirror' command, the resulting partition on the 'good' drive appears to be blank and asks me to format it. Bummer!

Now, the support guy tells me I should backup the bad partition onto the free one, but before doing so, I am asking, is there any chance of recovering the data on the seemingly blank partition now? I did not get any prompts from Windows asking me if I was 'sure' that the data would be lost, only the warning that the disks will not be 'redundant' anymore.

I would appreciate any insight.


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You were implementing the RAID how? Particular network card? Software based? Windows built-in RAID? – Bart Silverstrim Aug 17 '10 at 16:12
I'm guessing Software based. based on the last sentancein the second paragraph. – Nate Aug 17 '10 at 16:13
Why would they be asking you to "mirror" data from a known bad drive to the good drive, with corruption along with it? – Bart Silverstrim Aug 17 '10 at 16:13
You could try putting the disk in a computer and booting a Linux bootable disc with it and run Testdisk to see what you can find, but be aware that attempts to retrieve data can end up corrupting the drive more. – Bart Silverstrim Aug 17 '10 at 16:14
Also, there's a possibility (someone here knows more about it no doubt) that the drive is just tagged with a special flag as "RAID", so the standard drive access is seeing it as blank or corrupt when in reality it's just expecting it to be part of a mirror RAID. Does the "bad" drive show up with data and can it be read without problems? – Bart Silverstrim Aug 17 '10 at 16:15

Mirroring:data safety == TSA uniform:flight safety. Windows mirror setups are often all but useless in practice, since whatever corrupts one drive can easily corrupt the other. You're better off to use the second drive as permanent backup media and keep backups as often as practical.

Depending on your actual Windows OS [and the precise details of your dedicated host, which may not be dedicated after all], you may be able to inspect the drive using some other tools. If the data was ever actually on the drive, some form of sector recovery tool might allow you to get the data back. If it shows as blank, it may be just that the filesystem structure is missing from the drive. Have you used fdisk to have a look? There are several windows based recovery tools that might be able to recreate the drive structure.

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Yes, try connecting the drive to a computer and try accessing it using one of the free file recovery tools. I was actually just in the middle of installing PC Inspector File Recovery to recover data from a flash drive. It's a Windows based free/basic file recovery tool. – USACASD Aug 17 '10 at 22:49
Hmm... I've had very good luck with Windows software RAID all the way back to NT 4.0. It's true that I've had it faithfully "replicate" filesystem corruption onto both members of a RAID-1 set, but I'd had hardware RAID controllers do that do. For an "on the cheap" solution to make a server fault "resilient" against single disk failure, though, Windows RAID 1 works pretty well and the price is right for me. – Evan Anderson Aug 19 '10 at 0:28

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