> I think by tapedev=/no/such/tape Paul meant that literally, or at
> > least some string that could not be a legit tape device.

Not speaking for Paul, but I guess he did.

> >> # find /tmp/amanda -type f | xargs grep '/dev/rmt/0'
> >>
> >> and got nothing except the alternative "weekend" configuration I had
> >> played with the previous weekend.

I was looking the same direction, in fact I could not see any place
where Amanda logs the tape device she is going to use. The only bits
that would log the name of the tape device used are amcheck -t and
amrecover. I checked the config logs too /var/amanda/daily but nothing
there either.

> >> 4. There are additional parameters in my configuration that end up
> >> overriding my attempt to override tapedev?
> My AIT drive is /dev/rmt/1n, and the changer for it is addressed as
> /dev/scsi/changer/c7t0d0 in amanda.conf.

Can't there be an interaction between the changer and the tape drive?
That is the changer will anyway load the requested tape (changer names
has not been overwritten) and let Amanda know that the requested tape
is available at that known tape device, then Amanda using the device
provided by the changer rather than the one configured/overwritten?

You could try overwritting the changer too.

Bests,

Olivier