Path: utzoo!attcan!uunet!crdgw1!rpi!zaphod.mps.ohio-state.edu!uwm.edu!ogicse!intelhf!agora!billsey From: billsey@agora.uucp (Bill Seymour) Newsgroups: comp.sys.amiga.tech Subject: Re: Recovering data from hard disk Message-ID: <1990Sep17.221956.15323@agora.uucp> Date: 17 Sep 90 22:19:56 GMT References: Distribution: comp Organization: Open Communication Forum Lines: 61 In article nix@stekt.oulu.fi (Tero Manninen) writes: :I seem to have a nasty problem with my 30M Seagate.. :This began when my other hard disk stopped to work (the 20M drive :inside A590) and I tried to reformat it. Accidentally I formatted a :few cylinders from my healthy scsi disk (not low level format). :The scsi disk had two partitions in it and both were after that :"Not a DOS disk" :-( :So I tried to set partition information back with Supra controller :(I had not reformatted the disk after I switched to A590 controller). :But still no luck.. : :Now when I am trying to recover the files from the second partition :I get DiskSalv errors (the block difference stays at 202 blocks): : FILE ":LOOSE-BLOCKS/DIRBLK-20800/indent.doc.Z" Block Key Mismatch: : 21066 != 20864 : :With the first partition I get errors like this (diff 102 blocks): : FILE ":LOOSE-BLOCKS/DIRBLK-10406/Calc" Block Key Mismatch: : 10332 != 10434 OK, what it looks like has happened here is you have the break between the first partition and the second partition offset by a cylinder or two. Take a look at the drive info (blocks/track and number of surfaces) to figure out exactly how many cylinders they are off from what they're supposed to be. Then use SupraFormat to move the ending cylinder on the first partition and the starting cylinder on the second partition to reflect this. you should be able to reboot and find pretty much everything under a 'normal' filesystem. The few cylinders that got formatted won't have data on them, and any files that were stored in that area won't be recoverable. It's also possible that the drive parameters are different between the two controller softwares. I know that my Maxtor XT-3280S which has 1224 cylinders, 25 sectors/track and 15 surfaces shows up on the 3000 as 1310 cylinders, 350 sectors/track and one surface. Very close to the same number of total blocks, but confusing at times... :The recovered files are pure garbage.. I suspect that they are 202 and :102 blocks off the real data. :Is there any way to change this block offset ? :I already tried to change disk partitioning but it works by cylinders, :not blocks.. Again, tweak the drive parameter info to make a change in the nuber of cylinders match the number of blocks you need. The drive parameters you come up with don't have to actually match the physical drive, since SCSI just works on logical block numbers... :Oh, I was just to forget.. the DiskSalv is v1.42, very nice program. : :++Tero -- -Bill Seymour ...tektronix!reed!percival!agora!billsey ============================================================================= Bejed, Inc. NES, Inc. Northwest Amiga Group At Home Sometimes (503) 281-8153 (503) 246-9311 (503) 656-7393 BBS (503) 640-0842