> -----Original Message----- > From: Greg Freemyer [mailto:greg.freemyer@xxxxxxxxx] > Sent: Wednesday, December 03, 2008 6:06 PM > To: David Lethe > Cc: Paul Schriever; linux-raid > Subject: Re: raid5 failed logical and physically; how to reconstruct? > > On Wed, Dec 3, 2008 at 4:26 PM, David Lethe <david@xxxxxxxxxxxx> wrote: > >> -----Original Message----- > >> From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- > >> owner@xxxxxxxxxxxxxxx] On Behalf Of Paul Schriever > >> Sent: Wednesday, December 03, 2008 2:52 PM > >> To: linux-raid > >> Subject: raid5 failed logical and physically; how to reconstruct? > >> > >> Hi all, > >> > >> having used mdadm and linux for slightly over a year now to great > >> pleasure I came to face a problem. My raid5 got degraded due to hard > >> disc failure. After this some form of logical damage also occurred. > >> > >> Everytime I wish to mount md0 I get an error from the system telling > >> it's unable to mount, something wrong with the superblock. > >> > >> I tried to rebuild the array, without formatting the discs, and > using > >> a windows based tool I can still see that data is available, but > >> garbled. > >> > >> Is there any way of recovering the array, and to recover my data? I > am > >> not a big linux guru and any tutorial / steps to take would be very > >> much appreciated! > >> > >> yours > >> > >> Paul > >> > >> -- > >> To unsubscribe from this list: send the line "unsubscribe linux- > raid" > >> in > >> the body of a message to majordomo@xxxxxxxxxxxxxxx > >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > Well, there are ways to recover it, but it comes down to how much > damage > > you started out with; what damage (if any), the windows-based tool > > might have done; whether or not you have unreadable blocks on > surviving > > disks. If you just force a rebuild onto the new disk drive, then > you > > will absolutely make it worse. > > > > If data loss could be in the thousands of dollars range, then I > wouldn't > > use a cookbook recovery. Somebody who knows what they are doing and > who > > is directly involved will get more of your data back, and can look at > > the raw blocks to see what is going on. They may also look at the > disk > > that "failed" and perhaps get data from that disk. > > > > I would immediately make raw copies of each physical device before > going > > further. Hopefully you can pick up a cheap 1TB SATA disk and dd > > everything onto it. Not only can you play with a copy of the data, > but > > since you just lost a disk drive, then odds are high that another > disk > > in the RAID set will die. Just one more drive failure and you have > > 100% data loss. > > > > David > > Assuming the gurus here can't help you -- > > If you put the above dd images onto a NTFS based partition, then you > can buy Raid Reconstructor from RunTime Software for about $100 and > try to rebuild your via it. There is a free trial that you can test > with I believe. I've forgotten if you can actually attempt a rebuild > via the trial product. > > It runs in Windows thus the need for NTFS to hold the dd images of the > physical drives. > > Good Luck > Greg > -- > Greg Freemyer > Litigation Triage Solutions Specialist > http://www.linkedin.com/in/gregfreemyer > First 99 Days Litigation White Paper - > http://www.norcrossgroup.com/forms/whitepapers/99%20Days%20whitepaper.p > df > > The Norcross Group > The Intersection of Evidence & Technology > http://www.norcrossgroup.com It will not let you do a rebuild for free .. I can verify that. This is a good product, BTW, and I use it myself at times. One gotcha. Since you have a dead disk drive, then the reconstructor won't be of any help when it comes to corruption. That is because you have no parity to do XOR testing against. Depending on the amount of damage, it may have problems figuring out the sequencing of the disks; and if you have more than one partition on each disk, then the software can't handle it. David -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
