Herbert West, Hard Disk Reanimator
May 13, 2006 1:08 PM Subscribe
How do I recover data from dead hard disks myself?
In theory I am open to hearing about low-cost hard disk recovery options also -- the few times I have tried, prices were all in the hundreds of dollars. (Part of my problem with this is that, while it's indispensible when you really need it, the solution doesn't _scale_. Next time a disk bites the dust, while you were too busy to make sure it was backed up, or all the backup drives also died, or whatever, any money that you paid previously doesn't help).
Techno-nitty gritty: I am quite familar with Knoppix, and have a variety of ordinary adapter-type equipment like USB enclosures. The drives that I need the data from do not mount in Knoppix or Windows, and I am not sure why. The Knoppix logs talk about cryptic SCSI error codes. Unfortunately the problems do not seem to be software-related, as far as I can tell.
I am open to spending some money for specialized equipment to make the recovery process easier (the pros must be using some gear, and it might not be out of range). I am also interested in Howto type guides.
Thanks.
In theory I am open to hearing about low-cost hard disk recovery options also -- the few times I have tried, prices were all in the hundreds of dollars. (Part of my problem with this is that, while it's indispensible when you really need it, the solution doesn't _scale_. Next time a disk bites the dust, while you were too busy to make sure it was backed up, or all the backup drives also died, or whatever, any money that you paid previously doesn't help).
Techno-nitty gritty: I am quite familar with Knoppix, and have a variety of ordinary adapter-type equipment like USB enclosures. The drives that I need the data from do not mount in Knoppix or Windows, and I am not sure why. The Knoppix logs talk about cryptic SCSI error codes. Unfortunately the problems do not seem to be software-related, as far as I can tell.
I am open to spending some money for specialized equipment to make the recovery process easier (the pros must be using some gear, and it might not be out of range). I am also interested in Howto type guides.
Thanks.
In general, SCSI drives are mechanically very tough. Absent some compelling evidence the drives have been intentionally physically damaged, low level formatted, or otherwise disabled, it's quite likely you're really just having basic SCSI chain problems. Depending on the drive jumper settings, firmware options, and configuration commands, the controller boards on the disks maybe even be preventing the drives spinning up (waiting for initiation commands) or spinning the drives back down after a failed unit start sequence.
It pays to carefully sort out SCSI chain problems, methodically. Replace cables, put active terminators only at bus ends, set drive jumpers for unique SCSI ID's in the 1-6 range, and let each drive supply term power. Use your SCSI controller's setup firmware to probe the bus for expected target ID's, and make sure that low data rates and sync speeds are chosen at set up time.
Posting particulars of drive model numbers, jumper settings, and SCSI controller would help in making decent suggestions.
posted by paulsc at 3:12 PM on May 13, 2006
It pays to carefully sort out SCSI chain problems, methodically. Replace cables, put active terminators only at bus ends, set drive jumpers for unique SCSI ID's in the 1-6 range, and let each drive supply term power. Use your SCSI controller's setup firmware to probe the bus for expected target ID's, and make sure that low data rates and sync speeds are chosen at set up time.
Posting particulars of drive model numbers, jumper settings, and SCSI controller would help in making decent suggestions.
posted by paulsc at 3:12 PM on May 13, 2006
When eriko says "freeze" he really means put in a freezer, and freeze it.
posted by public at 3:16 PM on May 13, 2006
posted by public at 3:16 PM on May 13, 2006
Response by poster: SCSI is a red herring. When using Knoppix, USB drives (ie, a drive in a USB enclosure) show up as SCSI devices, but the disks themselves are all IDE.
posted by portabella at 4:37 PM on May 13, 2006
posted by portabella at 4:37 PM on May 13, 2006
This thread is closed to new comments.
1) Remove platters from bad drive.
2) If in good shape, install either in a good drive that they have, or in a jig, one platter at a time. Read data.
3) If not in good shape, use special equipment to read what they can.
4) Do all this in a very clean room, because any bit of dust between the spinning disk and the head destroys data.
What you can do at home.
1) If it is a bad contoller board, and you have an identical drive, right down to the revision, you can swap them.
2) If it won't spin, you can freeze the drive or whack it on power up.
3) If it still won't spin, and you don't care about the data, you can take the top off, power up the drive, and try to flick-start it. Touch only the hub.
In short, the reason it costs so much is that it requires lots and lots of very expensive gear, a very expensive room to put all that gear in, and lots and lots of time, esp. for damaged platters.
Dump some of those SCSI error codes here -- it might tell us what's wrong with the drive.
posted by eriko at 1:33 PM on May 13, 2006