On Thu, 04 Nov 2004 12:28:11 -0600, Eric Schnoebelen <eric AT cirr DOT com> 
wrote:
>         One thing that chg-scsi seems to need, and I didn't see
> in the configuration file, is a non-blocking control device for
> the tape drive, in addition to the blocking device node used for
> writes..  On linux, the sg* device corresponding to the tape
> drive is a good one to try.  On NetBSD, the `enrst?' device is
> the one to use..

Hrm - interesting I'm on linux.  I had been using /dev/sg1 as the
changer device and /dev/nst0 as the DLT drive.  See here:

lpdlnx00 dev # ls -la sg*
lr-xr-xr-x  1 root root 36 Oct 29 01:56 sg0 ->
scsi/host0/bus0/target0/lun0/generic
lr-xr-xr-x  1 root disk 36 Oct 29 01:56 sg1 ->
scsi/host1/bus0/target1/lun0/generic
lr-xr-xr-x  1 root root 36 Oct 29 01:56 sg2 ->
scsi/host1/bus0/target3/lun0/generic

and...

lpdlnx00 dev # cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
  Vendor: QUANTUM  Model: ATLAS10K2-TY367L Rev: DA40
  Type:   Direct-Access                    ANSI SCSI revision: 03
Host: scsi1 Channel: 00 Id: 01 Lun: 00
  Vendor: ADIC     Model: FastStor DLT     Rev: D116
  Type:   Medium Changer                   ANSI SCSI revision: 02
Host: scsi1 Channel: 00 Id: 03 Lun: 00
  Vendor: QUANTUM  Model: DLT7000          Rev: 2561
  Type:   Sequential-Access                ANSI SCSI revision: 02

By cross-referencing those two, you would think tha the DLT drive
could be accessed at /dev/sg2, correct?  Well, at first, that didn't
seem to be working:

lpdlnx00 dev # mt -f /dev/sg2 status
/dev/sg2: Operation not permitted

However, I just tried putting /dev/sg2 into my chg-scsi.conf.  I
re-ran amcheck, and not it appears that it's actually doing something.
 We'll see how this turns out after it finishes.