Subject: Re: SONY SDT-7000 DDS-2 drive issues
To: None <netbsd-users@NetBSD.org>
From: Matthias Scheler <tron@zhadum.de>
List: netbsd-users
Date: 11/16/2004 04:53:40
In article <4192F9D2.2060105@berklee.edu>,
	Louis Guillaume <lguillaume@berklee.edu> writes:
> I have a SONY SDT-7000 DDS-2 tape drive...
> 
> st0 at scsibus0 target 0 lun 0: <SONY, SDT-7000, 0148> tape removable
> st0: drive empty
> st0: sync (100.00ns offset 15), 8-bit (10.000MB/s) transfers

I had one those, too. I have an SDT 9000 now.

> ... but for some reason I cannot change the density to the correct code 
> for DDS-2, i.e. 36...

Why would you want to do that? Just insert a DDS-2 tape and it will do
the right thing. I've never set the density code of my SDT 9000 and
it writes DDS-1, DDS-2 and DDS-3 tapes just fine.

> If anyone can shed some light on a reasonable scenario for backing up to 
> these types of drives it would be very helpful...

I use a script which invokes "dump".

> . Will this drive return "end of media" signals?

Yes, if you use "mt eew 1" before starting the backup.

> . How to tell the length of tape so I can avoid using "-a" with dump?

You don't know the tape length in advance really. It depends on the
effectiveness of the hardware compression and one the speed the data
is delivered to the tape drive. If the tape drive has to start and stop
a lot because the computer delivers the data too slowly it will reduce
the capacity.

	Kind regards

-- 
Matthias Scheler                                  http://scheler.de/~matthias/