Gene Heskett wrote:

> Be aware that for many tape formats, the compression status is saved
> in a hidden header of the tape, so that once its been written in the
> compression on mode, that will be restored to on when the
> tape is loaded regardless of your wishes unless specifically disabled.
> 
> I had a script at one time that turned these flags off, and it looked
> something like this:
> 
> #!/bin/sh
> mt -f /dev/nst0 rewind
> dd if=/dev/st0 of=./scratch count=1
> mt -f /dev/nst0 defcompression off (or 0 depending on your mt)
> mt -f /dev/nst0 compression off (or 0 depending on your mt)
> dd if=./scratch of =/dev/nst0
> dd if=/dev/zero of=/dev/st0 count=(your drives buffer size plus 1)
> dd if=/dev/st0 (should show the tape label unchanged from ./scratch)
> 
> Note use of /dev/st0 for its automatic rewind in places. simplifies
> the script..

Gene, thanks a lot, I think this should go into the FAQ soon.
Could you (or somebody else) write some additional intro about why and
when this procedure is necessary?

This would help a lot, thanks.

Greets, Stefan