[net.unix-wizards] short blocks on SI 9700 ctlr with STC tridensity transport

dunigan@ornl-msr.arpa (02/07/86)

Dump and tar to STC tri-density tape drive via SI 9700 controller
on 4.2 unix (through ut.c driver) is losing a byte on some writes,
some blocks are only 10239 rather than all being 10240.  Seems
to be a function of the start-stop nature of tar and dump, a simple
tape-certify program writing from memory does not exhibit the
problem.  Happens at 1600 and 6250, and if you re-write the tape
the short blocks occur at different places -- but re-reading
always reports the same sequence  (reading on another tape
subsystem reports the short blocks)

  hints or suggestions?

tom
  dunigan@ornl-msr.arpa

ron@BRL.ARPA (Ron Natalie) (02/07/86)

We use SI 9700 controllers with the 125ips STC drives on many systems
at BRL and we have never seen this problem on either 4.2 or other UNIX
systems.


-Ron

leon@mmm.UUCP (Leon Schilmoeller) (02/10/86)

> 
> We use SI 9700 controllers with the 125ips STC drives on many systems
> at BRL and we have never seen this problem on either 4.2 or other UNIX
> systems.
> 
> 
> -Ron

We have the SI 9700 Tridensitey drive also, and have not seen this problem
either.  We are running BSD 4.2 on a VAX 11/780.

Leon Schilmoeller
3M - St. Paul Mn
ihnp4!leon