Ross Vandegrift wrote:

> On Sun, Aug 06, 2006 at 09:41:39AM +0200, Geert Uytterhoeven wrote:
> > > I've had quite good luck doing poor man's data recovery.  Boot the
> > > machine into Knoppix or like ilk and use dd_rescue to copy the disk to
> > > an image file or another disk.  dd_rescue is smart about skipping
> > > areas of the disk it cannot read instead of giving up.  It can take a
> > > long time, but I've recovered quite a bit of data with that sucker.
> > 
> > But this simple methods won't work, as the disk used to be part of a RAID0
> > setup, and thus contains only half of the data. Then it depends on the 
> > stripe
> > size: the larger it is, the more likely you can find useful pieces of data
> > (e.g. a complete password or credit card number).
> 
> Well, no reason you couldn't apply this principle to the RAID0 data.
> Suppose your disks are /dev/sda1 and /dev/sdb1, sdb has failed:
> 
> # dd_rescue /dev/sdb1 some_file_or_device


This is besides the point, but that wont work, and I'm not sure if you
completely understand the situation. I *DON'T* want data to be
recovered from the drive, and because I'm returning it under warranty, I
want the data on it to be destroyed.

I can't erase it, because if anything accesses the drive, it makes loud
grumbling noises and vibrates, then the whole computer locks up seconds
later, with the following in dmesg:

ata2: status=0x51 { DriveReady SeekComplete Error }
ata2: error=0x40 { UncorrectableError }
end_request: I/O error, dev sdb, sector 18944
Buffer I/O error on device sdb, logical block 2368

I'm quite sure the only way to recover from it is to transplant the
platter into an identical good drive,  assumming it isn't physically
scratched.  Then I think gnu `strings' can be used on the raw device,
and get at the stripe sized text fragments.  There is 0.5 probability
that my passwords are there in plain text, which is what I'm now worried
about.  I've already extracted the backups to the good drive, so I can't
check that to see what's not on the dead drive.

If I'm feeling lucky, when I get the new drive, I could try the
transplant operation, carefully reset the warrantly violation detection
stickers, and send the clean platter back in the dead drive. It's an
"Advance" RMA, where they send me the new drive first so I can use
approved packaging for the return.

Or I could just hope whoever finds it whereever dead drives go, isn't
curious enough to see if anything is on it, and use encrypted loopback
devices from now on...

Laurence