[sane-devel] Partition table gets altered

[Henning Meier-Geinitz]

Hi,

On Tue, Nov 27, 2001 at 06:44:42PM +0200, Jani Salonen wrote:
> I'm not sure is this problem caused by XSane or some SCSI module, but when I
> start XSane without my scanner (Epson perfection 1640) turned on or
> disconnected, the partition table of my HD messes up, and there is no any
> partitions visible anymore. although this can be fixed afterwards with fdisk,

Oops. If this is really a SANE bug, it will be in sane-backends and
not XSane. Probably /dev/sg0 (or whatever points to your scanner if
it's turned on) points to your SCSI disk if the scanner is not
connected. So all the SANE backends access the disk and not the
scanner. In theory, that shouldn't cause any trouble because the
backends usually do only an inquiry command. Last time I checked I had
no problems with my SCSI disks but that was about one year ago.

One thing that may go wrong is that a backend "thinks" /dev/sg0 is a
USB scanner. I'm not sure what happens if this is true but this may
have such consequences.

Please make sure that you don't have links like /dev/usbscanner or
/dev/usb/scanner pointing to /dev/sg0 or similar. Also make sure
that you don't have "usb /dev/scanner" (with /dev/scanner pointing to
/dev/sg?) or "usb /dev/sg0" in your epson.conf. 

If this doesn't solve the problem, could you please try to comment out
"epson" from dll.conf and try again?

I would make a backup of the master boot record/partition table (I
think something like "dd if=/dev/sd0 of=backup.bin bs=512 count=1"
will work, but check the documentation.

Bye,
  Henning