I've been trying to coax an old Exabyte 8mm tape drive that I borrowed
into doing some backups on my machine.  For the most part it seems to
work.  But sometimes weird things happen.

For instance, if I load a tape and tar onto it, things go fine.  I did
a tar verify and a tar --diff afterwards and everything was pretty
much peachy.  Using "mt -f /dev/rst0 rewind" worked as advertised.
However, "mt -f /dev/nrst0 fsf" would always put the tape in an
unwritable mode.  I could read it after that, but every write would
fail with "Invalid command" or something like that, with a syslog
message:

Apr 11 00:58:55 MindBender /netbsd: st0(bt0:6:0): illegal request

If I rewound and ejected the tape, then stuck it back in and just used
tar to read past the first backup, I could write a second backup with
no problems.  But using mt fsf would make the tape unwritable.

Also, after it got into this weird state, sometimes it would give me
"Invalid command" when I tried other mt commands too (like rewind),
but if I tried the command a second time, it would usually work.

I'm using a bt747s with a kernel built Friday from the 4/8 sup.  Is
the tape handling really buggy?  Or is there something else that could
explain all this odd behaviour?

				--Michael

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 Michael L. VanLoon                 Iowa State University Computation Center
    michaelv@iastate.edu                    Project Vincent Systems Staff
  Free your mind and your machine -- NetBSD free Un*x for PC/Mac/Amiga/etc.
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