Exabyte vs. Ultrix 3.1

[Don Kossman]

In article <3064 at rti.UUCP> shaddock at rti.UUCP (Mike Shaddock) writes:
>We have a DILOG SQ703A tape controller with an Exabyte 8mm tape drive
>(prom 4$22) attached to VAXstation II running Ultrix 3.1.  Under Ultrix
>2.2, the Exabyte worked perfectly, but since we upgraded to Ultrix 3.x
>it has not worked very well.  It understands commands like "mt -f
>/dev/rmt1h rewind" or "mt -f /dev/rmt1h offline", but dd, tar, and dump
>all fail in a moderately strange way.  Tar will begin to write on the
>tape, but then will come back with:
>
> (error messages and config file deleted)
>
we've been using an exabyte 8mm drive with a controller from
Contemporary Cybernetics (model Cy-8200-Q) on a MicroVAX-II
under Ultrix 3.0 for several months.

we did have some initial write errors with dump, reported these
to the vendor, got a controller upgrade, and have had no problems
since then.   dump/restore work perfectly.  we are getting
about 10 megabytes per minute on our poor old MVII.  combinations of
tar and mt work reasonably well (have to use "mt fsf 1" when writing
multiple tar archives to the non-rewind device, and sometimes the tape
positioning gets messed up as the tape is unloaded/loaded).  this
is to be expected, perhaps (?) with 8mm technology.  we're
waiting for DAT, which will give us slightly lower speed but
true random access (ie "tar r" should be possible).

don kossman, sei information technology, los angeles
...sun!suntzu!seila!don