[comp.sys.hp] SUMMARY: strange

edwin@cs.ruu.nl (Edwin Kremer) (12/18/90)

Thanks very much to those who responded so quickly to my notes about
a somewhat strange behaviour of our DAT drive!

I'll start this summary some notes to clarify a couple of things that
should have appeared in my original message, but didn't:

	1) The DAT is a very new product. Late intro of the DAT in the
	   HP-UX 7.0 program caused its documentation not to make it
	   into the HP-UX 7.0 documentation set.
	2) You can buy two types of DAT drives: a stand-alone (unpack,
	   plug-in and play) version and a bare DAT unit that nicely fits
	   into the HP Series 6000 Mass Storage Systems (models 330S and
	   660S). We bought the latter one.
	3) Installing the DAT hardware was thoroughly documented in the
	   doc that came with the mass storage unit mentioned above.


Well, of course HP _knew_ that the DAT installation from the OS point
of view (device major/minor numbers, what to put in "/etc/conf/dfile",
etc.) wasn't documented in the HP-UX 7.0 manual set, so Paul Perlmutter
<paul@hppaul.fc.hp.com> wrote up a thorough summary, called "the DDS
Application Note".
  Unfortunately, this invaluable document was shipped with the stand-alone
DAT drive version only, not with the bare unit. So, we were just unlucky ;-)

Anyway, Paul Perlmutter mailed me an electronic copy of this document
that indeed clarifies a lot. Well done and thanks very much Paul!

In a followup to my message, Paul Perlmutter also states that:

	|> This is a bug in the 7.0 DAT driver.  It can be safely ignored.
	|>   The reason? After the tape is successfully ejected, the driver
	|> during the tape "close" routine will issue a reposition command
	|> to the non-cartridge and the request fails.


Sven Thjostarsson <award@uafhp.uark.edu> offered the following:

	|> Try: mt offl
	|> 
	|> I know that you are supposed to use mt on 0mn, not 0m. It will
	|> choose the proper device if you don't specify one in your case.

I verified this of course and he's right. If you used the default naming
scheme (/dev/rmt/0m and /dev/rmt/0mn), you do not have to provide device
names to the 'mt' or 'tar' commands. 'mt' will use the non-rewinding
device by default.


Well, that's it. I'm impressed by the amount (and speed) of support I got
from Paul Perlmutter in just one day. Great!


	thanks again and Merry Christmas,

						--[ Edwin ]--
--
Edwin Kremer (SysAdm), Dept. of Computer Science, Utrecht University
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