blocksize error on sa

[Dan Langille]

In my attempts to track down the pthreads problem related to EOT not being
properly returned, I've installed a QIC tape into my Bacula
(http://www.bacula.org/) development box:

FreeBSD undef.example.org 5.1-CURRENT FreeBSD 5.1-CURRENT #1: Wed Sep
10 14:43:34 EDT 2003 dan at undef.example.org:/usr/obj/usr/src/sys/UNDEF i386

sa0 at ahc0 bus 0 target 2 lun 0
sa0: <WANGTEK 51000  SCSI M74H 12B3> Removable Sequential Access SCSI-CCS
                                     device
sa0: 3.300MB/s transfers

With a tape in the drive, I attempt a status:

# mt -f /dev/sa0 status
mt: /dev/sa0: Invalid argument

This appears in /var/log/messages:

Sep 14 11:59:23 undef kernel: (sa0:ahc0:0:2:0): unable to set fixed
blocksize to 1024

Similar entries appear for rewind, offline, retension.

Archive seaches lead me to believe the problem is related to the drive not
knowing that the device needs a particular blocksize.  But I can't set the
blocksize using "mt blocksize" (it gives the error mentioned above).

Ideas please?