Subject: Re: Tape library or DLT support in FreeBSD/NetBSD
To: Matthew N. Dodd <winter@jurai.net>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: netbsd-help
Date: 04/25/1996 10:52:38
On Thu, 25 Apr 1996 04:07:46 -0500 (CDT) 
 "Matthew N. Dodd" <winter@jurai.net> wrote:

 > >     Of prime importance is OS support for the unit.  :)  Has anyone
 > > successfully used something like the HP C1553A or the Conner 4586NP
 > > autoloaders?  I have a script that uses FreeBSD's scsi(8) command to
 > > change cartridges on the C1553A, but that still requires some sort of
 > > operator intervention.  Something like a DLT4000 unit would be great
 > > if I can access it through /dev/nrst0 like any other SCSI tape drive.
 > > Thanks in advance for any recommendations.

For the record, I wrote a new SCSI changer driver for NetBSD (and ported it
to FreeBSD, though I haven't submitted the PR to the FreeBSD guys, yet) and 
userland program to control the changer.  It's been thoroughly tested 
under NetBSD-current and FreeBSD-2.1 with a Conner changer coupled with 
an Archive Python DAT.  On the particular changer I used, the tape drive 
was at lun0 and the changer at lun1 (which caused at least a little 
trouble, given the autoconfiguration scheme employed by the FreeBSD SCSI 
code, but is work-around-able).

The new ch driver should work with any model of SCSI changer that follows 
the SCSI changer spec.  For users of NetBSD-current, see the chio(1) 
manual page.

 > I don't see why it shouldn't work...  It would probably
 > be pretty straight forward to get Amanda to work with either solution.

The fellow I wrote the driver for is using it for automated backups, and 
it's working Great.  Using the FreeBSD scsi(8) command is sort of ugly 
for manipulating a changer, since there's nothing there to keep state for 
you.  The new ch driver takes care of all of this.

Anyhow, I'll try and get the FreeBSD version packaged up and sent off today.

--------------------------------------------------------------------------
Jason R. Thorpe                                       thorpej@nas.nasa.gov
NASA Ames Research Center                               Home: 408.866.1912
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