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RAID-1 Disks Corrupted - File recovery recommendations?

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May 21, 2010 12:40:27 AM

I've totally screwed up! I STUPIDLY did not make a recent backup, and now am desparate to acccess files. I hope that someone can help me as to what to do!

I had a functioning mirrored RAID 1 setup with Win XP using the onboard (AMD) RAID controller. The disks were divided into two partitions, one for the OS, and one that was not formatted.

I tried to boot off of only one of the two discs, and things went to hell from there. I tried booting using the BIOS set at all three modes - RAID, AHCI, and IDE. I (stupidly) entered the RAID controller to try re-assigning one drive and that probably fried it. I tried using windows "recovery console" but it doesnt see any windows installation on the disk. I then used the "fixmbr" command on that disk, then I tried the "FIXBOOT" command, and now that disk shows as a corrupted partition table and is completely inaccessable.

I havent (yet) totally fried the other disk - it shows up under Windows Explorer in Win7, but is inaccessable. Looking at the disk under "Disk Management" in "computer management" shows the OS partition still exists, but it is labled as "RAW" instead of NTFS or FAT32. Can anyone help me to figure out how to access the files on that disk?

THANK YOU IN ADVANCE for ANY help!

Gigabyte MA78GM-US2H motherboard (rev. 1.0 with AMD 780G + SB700 Chipset)
AMD Kuma 7750 processor (passive cooling for QUIET!)
4 gigs ram
OCZ Vertex 60gb SSD w/ windows 7 (now)
WAS: Windows XP on 2x 250gb Samsung hard drives in RAID 1, now corrupted!
a b G Storage
May 21, 2010 5:46:03 PM

Put the array back and try to rebuild it.
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a c 342 G Storage
May 22, 2010 4:55:32 AM

Find the detailed instruction manual for your on-board RAID system and read it thoroughly. I don't have an AMD RAID chip. But the system I do have has a very good way to recover from ONE bad HDD in a RAID1 array. Your BIOS port mode must be set to use RAID (not IDE Emulation, or AHCI, etc.) on the hard disks you have. Then with both HDD's installed you push a particular key during early boot when prompted on the screen and it takes you into the RAID management system. From there you can examine the RAID array, identify which of the two disks is faulty and which is still good. If there is ANY confusion here, do NOT proceed. But there usually is a process to restore the RAID1 array by simply copying EVERYTHING from the good disk that still works to the other.

As I said, this should be covered in the RAID manual. That MAY have been included in your system's mobo manual or as a document on the CD that came with your mobo. If it's not there, go to the mobo manufacturer's website and search for it for the specific mobo model you have. Or, go to the AMD website and look for it according to the Southbridge chip (SB700) you have.
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Anonymous
a b G Storage
May 22, 2010 6:28:32 AM

Try some recovery software like http://www.icare-recovery.com/ ?

Or

The redundancy of RAID levels is designed to protect against a disk failure, not against a power failure. There are several ways to recover from this situation.
Method (1): Use the raid tools. These can be used to sync the raid arrays. They do not fix file-system damage; after the raid arrays are sync'ed, then the file-system still has to be fixed with fsck. Raid arrays can be checked with ckraid /etc/raid1.conf (for RAID-1, else, /etc/raid5.conf, etc.) Calling ckraid /etc/raid1.conf --fix will pick one of the disks in the array (usually the first), and use that as the master copy, and copy its blocks to the others in the mirror. To designate which of the disks should be used as the master, you can use the --force-source flag: for example, ckraid /etc/raid1.conf --fix --force-source /dev/hdc3 The ckraid command can be safely run without the --fix option to verify the inactive RAID array without making any changes. When you are comfortable with the proposed changes, supply the --fix option.
Method (2): Paranoid, time-consuming, not much better than the first way. Lets assume a two-disk RAID-1 array, consisting of partitions /dev/hda3 and /dev/hdc3. You can try the following:
fsck /dev/hda3
fsck /dev/hdc3
decide which of the two partitions had fewer errors, or were more easily recovered, or recovered the data that you wanted. Pick one, either one, to be your new ``master'' copy. Say you picked /dev/hdc3.
dd if=/dev/hdc3 of=/dev/hda3
mkraid raid1.conf -f --only-superblock
Instead of the last two steps, you can instead run ckraid /etc/raid1.conf --fix --force-source /dev/hdc3 which should be a bit faster.
Method (3): Lazy man's version of above. If you don't want to wait for long fsck's to complete, it is perfectly fine to skip the first three steps above, and move directly to the last two steps. Just be sure to run fsck /dev/md0 after you are done. Method (3) is actually just method (1) in disguise.
In any case, the above steps will only sync up the raid arrays. The file system probably needs fixing as well: for this, fsck needs to be run on the active, unmounted md device.
With a three-disk RAID-1 array, there are more possibilities, such as using two disks to ''vote'' a majority answer. Tools to automate this do not currently (September 97) exist.
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