[rescue] VS80 DLT tape drive question

[Mr Ian Primus]

--- "Curtis H. Wilbar Jr." <rescue at hawkmountain.net>
wrote:

> It is not streaming well.... so not sure what I'd
> need to tweak (just using
> tar now under Linux).  I also only have it connected
> up to an Adaptec
> 2940U ... I would have though this drive does
> ultra... but dmesg seems to
> indicate it running at 10.0 MB/s.  Although I'd
> think that should be fine
> as it only backs up 3-6MB/sec (3 non compressed, 6
> compressed at 2:1).
> 
> It is the only device on the controller... so I
> think it should be fine...
> 
> Anyone have any success in tweaking parameters via
> mt/tar/etc to get them
> to stream well ?

A couple things - have you checked in the BIOS
settings for the Adaptec controller, and made sure
that it's set for higher speed mode on that SCSI ID?
Are you connecting it to the machine through a 50 pin
or 68 pin cable?

Since that drives should have a pretty good buffer,
this may not apply, but it helped me vastly when
dealing with an old SCSI TK50 under Linux:
mt -f /dev/nst0 drvbuffer 1
Turning on the host buffer made the TK50 write the
same data in about 1/20th the time. Before, it just
kept shoeshining.

-Ian