[comp.unix.ultrix] SI 9 track problems

stevem@pserv.CFSMO.Honeywell.COM (Steve Mestad) (05/03/90)

We have an SI 9625 dual ported tape drive with Aviv controllers on a 
Microvax II.  We are experiencing problems when using cpio on multi 
tape archives.  Cpio will prompt for the tapes on write and everything 
seems to be working ok.  But when reading the archive, cpio goes out of 
phase when it starts to read the second tape.  (For much of our tape 
work, cpio is the only utility that meets our needs.  Tar, dump, and 
the others dont have the necessary capabilities.)  EOT seems to be handled
properly for tar and dd.

Dec says cpio handles multiple tape archives just fine on their tape drives.
(SI's tape drive is supposed to emulate a TS11 drive.)  SI has checked into
things and even tried converting the drive to use a QS1000 controller (which
emulates TK50 and also didnt work properly.)  So far no progress in resolving
the problem.

My questions are:  Does cpio work properly on Dec drives?  If so, which ones?
Is anyone else out there using the SI tape drive?  Is cpio working for you?
If so, how are you making it work?  (Piping cpio through dd had a dramatic
unacceptable decrease in performance when we tried it.  It also seems to 
drop a bit of data at the end of the archive.)  Any suggestions of where to
go from here?  

Thanks.

Steve Mestad
stevem%pserv@src.honeywell.com

grr@cbmvax.commodore.com (George Robbins) (05/04/90)

In article <8@pserv.CFSMO.Honeywell.COM> stevem%pserv@src.honeywell.com writes:
> We have an SI 9625 dual ported tape drive with Aviv controllers on a 
> Microvax II.  We are experiencing problems when using cpio on multi 
> tape archives.  Cpio will prompt for the tapes on write and everything 
> seems to be working ok.  But when reading the archive, cpio goes out of 
> phase when it starts to read the second tape...
...
> Any suggestions of where to go from here?  

Well, I'd actually try it on a DEC drive and see if you get the same results.
If not, then dump the end of the first tape and the beginning of the second
tape and see how they differ.  One possibility would be that the SI drive isn't
successfully doing a backspace & write eof or whatever trick DEC is using to
indicate end of tape.

Another possibility would be to look at the portable archive (pax) utility that
Usenix has developed.  It handles both cpio and tar formats, and is available
in source form from various archives.

-- 
George Robbins - now working for,     uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing:   domain: grr@cbmvax.commodore.com
Commodore, Engineering Department     phone:  215-431-9349 (only by moonlite)