Tape drive handling on FreeBSD

[Matthew Jacob]

> The only problem I can imagine is if someone already uses O_NONBLOCK on an
> open() call and expects it to fail if there is no tape in the drive.  This
> seems a bit unlikely, but a bit of documentation can avoid most problems.



*cough*

Documentation didn't help you :-).

I'll try and do a bit of work on it over the next week or so but I can't
test until I get home and hook up a tape drive (and find a frickin' piece of
DTL media for it).

Poke me periodically at my private address.

> Is the problem here that you *don't* want to do 'space to EOD' when EOM is
> > issued? That is, you don't want to lose your actual relative tape
> position
> > information when seeking to append?
>
> Yes, exactly.  Since Bacula maintains the file/block positions of
> jobs/data in
> a catalog, it will refuse to append to a tape if the actual EOM of the
> tape
> does not agree with the catalog.  A discrepency can easily occur if, while
> writing a tape, the OS crashes (a power loss of course) ...



Can't use use block location stuff? Again- let's move this discussion to my
private mail address unless anyone else on freebsd-scsi wants to join in.