Re: [opensuse] Is there a way to read data from a hdd, with a worm eaten bootsector?

Carlos E. R. wrote:


The Monday 2008-06-30 at 13:59 -0400, James Knott wrote:

> By copying the sectors to another drive, you may be able to fix defective sectors by using a sector editor. If you mess up, you just start again on a copy, without having to go back to the original drive. By fixing the defective sectors, you may now be able to recover the data. If you operate directly on the defective drive, a mistake may make data recovery impossible. Again, if you can read enough for Spinright to work, you can read enough to copy the sectors and working on a copy is always safer than on the original. Also, in order to copy the original sectors from a defective drive, you need the appropriate tools that will make multiple attempts to read a sector etc., instead of just passing over the error. Any decent sector repair tool should be able to do that.

> Someone else mentioned "dd_rescue". Here's a link to it: http://www.garloff.de/kurt/linux/ddrescue

There is a case when certain type of programs, like probably that spinrite can help: when the magnetization is marginal or incorrect. It supposedly looks at the raw data, including sync marks, crcs, etc, on the surface of the disk, and tries to guess what the "payload" data should be.


Is that "raw data" available to the computer side of the disk interface (IDE, SATA etc.)? Back in the days when I used to repair disk drives (disk pack drives for mini-computers 20+ years ago) it certainly wasn't. You'd have to get right into the disk interface hardware with an oscilloscope to see that sort of thing.

This can not be done even by dd_rescue: what this one does is read several times and average the result. The disk firmware and the operating system hides the raw data of the disk, dd doesn't see it. They probably need manufacturer specs to decode that. If spinrite can really read this, then it is very different from linux tools. However, if what they say they do is babletalk and they are really doing something similar to dd_rescue, that's another thing.

-- Cheers,
Carlos E. R.


--
Use OpenOffice.org <http://www.openoffice.org>

--
To unsubscribe, e-mail: opensuse+unsubscribe@xxxxxxxxxxxx
For additional commands, e-mail: opensuse+help@xxxxxxxxxxxx

Relevant Pages

  • Re: Hard Disk Failure
    ... is so much stuff on the hard disk that I want to try to keep. ... tool on the drives and this is the result. ... Sectors per Cluster: 8 ... MFT Start Cluster: 786432 ...
    (microsoft.public.windowsxp.hardware)
  • Re: Summary of Recent Data Recovery Methods; Spinrite 5.0
    ... > I had a 3 gig hd with about 5-10% bad sectors. ... > most data and DP had no special recovery capabilities other than ... But you need to make up your mind: You either clone a disk as ... xcopy data off failing drives, ...
    (comp.sys.ibm.pc.hardware.storage)
  • Re: Hard Disk Failure
    ... is so much stuff on the hard disk that I want to try to keep. ... tool on the drives and this is the result. ... Sectors per Cluster: 8 ... MFT Start Cluster: 786432 ...
    (microsoft.public.windowsxp.hardware)
  • Some questions concerning defective sectors on an internal HD
    ... chkdsk found 12 KB of defective sectors on this drive (I ... chkdsk /r found the same 12 ... Perhaps I could save the data on several slower drives and then do a ...
    (comp.arch.storage)
  • Re: Summary of Recent Data Recovery Methods; Spinrite 5.0
    ... >>> recovery programs stalled or would take forever to scan disk. ... >>> capabilities other than skipping bad sectors. ... > that SR killed their drives. ...
    (comp.sys.ibm.pc.hardware.storage)