Tape backup woes (mt)... should I file a bug report?
I've got a tape drive for backups, and for a long time I was absolutely
unable to store more than a singe archive per tape.
Stop smiling, that's not funny.
Eventually and accidentally, I found out about rewinding and
non-rewinding device files, the information being hidden deep in the tar
info file. For all who don't know it:
> Most tape devices have two entries in the `/dev' directory,
> [... /dev/tape, /dev/ntape ...] The simpler name is the
> _rewinding_ version of the device, while the name having `nr' in it is
> the _no rewinding_ version of the same device.
> A rewinding tape device will bring back the tape to its beginning
> point automatically when this device is opened or closed.
So 'mt -f /dev/tape fsf 1' will first bring the tape to the beginning
of the second file, but once the command is finished the tape will rewind.
I don't usually use info, and from the occasional man-vs-info flamewar
on this list I know I'm not alone. Furthermore, I'd never have looked
for this in the tar documentation. Or do I use tar to fast-forward the
tape? All I knew to start with was that 'mt eom' apparently didn't work
IMO, the (non-)rewinding device issue should be mentioned in the mt
manpage. But does this omission really justify a bug report? Or is it
While I'm at it, one more thing I don't understand -- mt comes with the
cpio package, and there's another package mt-st one may install. I don't
notice any significant difference between the two, so where's the point?
Under what circumstances would I want or prefer mt-st over mt?