On Thu, Jun 19, 2003 at 11:47:53PM -0400, Jon LaBadie wrote:
> > I'm not sure what documentation you're referring to, but for every
> > compression-capable drive I've ever used (DDS2, DDS3, DLT-4000,
> > DLT-7000, DLT-8000, LTO-1) both the Solaris factory st driver and the
> > tape-vendor-supplied st.conf default to the highest-possible density
> > and compression factor.
> 
> Actually Jay the default can be specified in the st.conf file to match
> any of the "l", "m", "h", or "u/c" entries and for 15 of the 49 entries
> in my file the default does not correspond to the "u/c" mode.

Jon, you are exactly right, and I was... not.  :-)

In my (meager) defense, I did also mention "tape-vendor-supplied
st.conf default", and for example, the Quantum DLT/Solaris
recommendation is:

From:
http://www.quantum.com/AM/support/DLTtapeDrivesMedia/TechnicalDocuments/Default.htm

Where the Solaris install PDF does explain all the funky mode bits,

> If you are installing a DLT4000 add the following line:
      <DLTtape data> = 1, 0x38, 0, 0x8639, 4, 0x17, 0x18, 0x82, 0x83, 3;
> If you are installing a DLT7000 add the following line:
>     <DLTtape data> = 1, 0x38, 0, 0x8639, 4, 0x82, 0x83, 0x84, 0x85, 3;
> If you are installing a DLT8000 add the following line:
>     <DLTtape data> = 1, 0x38, 0, 0x8639, 4, 0x84, 0x85, 0x88, 0x89, 3;
> If you are installing a Super DLTtape add the following line:
>     <DLTtape data> = 1, 0x38, 0, 0x8639, 4, 0x90, 0x91, 0x90, 0x91, 3;

This is what I'm currently using for DLT, and it does default to max
density/compression, FWIW.

-- 
Jay Lessert                               jay_lessert AT accelerant DOT net
Accelerant Networks Inc.                       (voice)1.503.439.3461
Beaverton OR, USA                                (fax)1.503.466.9472