FL schrieb:

> After watching the trouble recur, I see that the device associated with
> the changer SCSI device ID moved: it was /dev/sg2, today it is /dev/sg1.
> No changes were made to the Exabyte LTO-2 tape library  or to the SCSI
> card (or anything else). So there is something I'm failing to understand
> about udev, SCSI or the Exabyte.
>  
> Perhaps during bootup I should attempt
>  
> mtx -f /dev/sg0 status
> mtx -f /dev/sg1 status
>  
> until I have a valid status, and link
> /dev/changer to that, then refer to /dev/changer in amanda.conf. That's
> a workaround: somehow the device assigned to the changer moves on
> occasion, after a reboot. Perhaps I should be referring to the changer
> device in some other way (bus number, SCSI ID, lun...).

Don't remember the used OS now:

Do you have something like udev on that box? You could then set up a
rule to get a fixed relation between devicename and device.

What else gets in the way? /dev/sg? are scsi-devices, on my boxes the
order is always the same, increasing with the SCSI-IDs.

Another idea would be:

chgrp tape /dev/sg?

in a start-script ...

Just quick thoughts.

Stefan