[NBLUG/talk] Recovering data from a failing hard disk

[Lincoln Peters]

On Mon, 2004-08-23 at 23:50, Kyle Rankin wrote:
> On Mon, Aug 23, 2004 at 11:10:21PM -0700, Lincoln Peters wrote:
> > Unfortunately, I've already started copying the data off the old hard
> > disk with cpio.  And I've copied 92/96GB at this point.
> 
> Ahh well if you far along already might as well go with that, but if your
> hard drive was spouting errors throughtout the copy, you might want to use
> something like dd_rescue.

It's not spouting a lot of errors, although I noticed a weird disk usage
issue (see the message I posted at 11:42PM this evening).  It hits an
I/O error occasionally, and seems to respond by padding the affected
file with zeroes and then proceeding to the next file.  At least I can
keep track of the damaged files and deal with them later.

> 
> > 
> > I don't think that dd_rescue would work in this case anyway because the
> > failing hard disk has a capacity of 160GB, and the new hard disk that
> > Maxtor sent me (as per the warranty) is 250GB.  I guess that, for
> > whatever reason, it was easier for them to send me a significantly
> > larger hard disk than one of the same size as the one that failed.  Not
> > that I'm complaining!
> 
> Well, you can actually use it for partition-to-partition copying, and then
> grow the filesystem (reiser, ext3 and XFS all have grow tools) or just dd
> to a single file, mount it loopback, and then copy stuff over. Lots of
> options really.

A combo of dd and a loopback mount would be impractical in this case,
since I would need a third hard disk that would be at least 160GB (my
second-largest hard disk is only 60GB).  A combo of dd and a "grow" tool
might do it, though, if I had to do it again.

> 
> Basically, dd_rescue is useful for making bit-for-bit copies when the hard
> drive is sometimes spitting out errors that make other tools exit.

I'll try to remember that, in case another hard disk fails.

---
Lincoln Peters
<sampln at sbcglobal.net>

Knowledge is power -- knowledge shared is power lost.
		-- Aleister Crowley