> 03/11/1999 10:02:22  ANR1411W Access mode for volume M01372 now set to
>
>                       "read-only" due to write error.
>
>
> 03/11/1999 11:13:13  ANR8820W Repairing VCR data for Volume M01372 in drive
>
>                       I35907 (/dev/rmt7); mount may be delayed.
>
> 03/11/1999 11:25:56  ANR8337I 3590 volume M01372 mounted in drive I35907
>
>                       (/dev/rmt7).

If you got a write error, where is the SENSE information?  It will tell
you something about the error, and if it is media or drive related.  Most
times they are "said to be" media related, and a cleaning of the drive
can prevent future errors.  The next mount of the tape should either
repair the VCR data for subsequent mounts, or fail, also providing SENSE
info.  At least this is my experience with the 3570's and IBMtape on Sun.

The Volume Control Region (VCR) is updated everytime the tape is written
to, at unload time.  If the tape is not unloaded properly, then the VCR
data is invalid, and has to be recreated.  This is done when ADSM mounts
the tape, and spaces to EOD.  Since it does not know where EOD is
anymore, this can take a long time, depending on how much data is on the
tape.  If the end of data is damaged, then the VCR data cannot be
repaired, and one should move the data to other tapes.  Once the volume is
scratched (empty), the VCR data is once again valid.  Don't throw away the
tapes, as they are quite expensive.  ;-)  If the VCR data is not
repairable, chances are pretty good that ADSM does not fully understand
what is on that tape, too, so the move data may not complete.  You may
have to issue a "delete vol M01372 discarddata=yes" after moving as much
data as possible.

Under Solaris, with the tapeutil program (comes with IBMtape device
driver), one can try to repair the VCR data outside of ADSM too.  I have
done this in order to then take a dump of the drive that it fails on, and
send the drive dump to Tucson for analysis.

I hope this helps.

Steve (unVMix Systems Programmer/Dude) Roder
(tkssteve AT ubvm.cc.buffalo DOT edu | tkssteve AT acsu.buffalo DOT edu | 
(716)645-3564 ,
   | http://ubvm.cc.buffalo.edu/~tkssteve)