Alan Altmark wrote:
According to the 3490 Hardware Reference, Error Recovery Action code 38
(physical EOT) specifically raises an Equipment Check. Intervention
Required can be turned on, too, if the problem is not corrected before the
CU presents status to the channel (and I don't know how you "recover" from
EOT).
Well..
What's odd then would be that VTAPE would present a Physical EOT before
having presented a Logical EOT (which is presented by a Unit Exception
in the SCSW Device Status on write ops).
Otherwise, that would mean that VTAPE isn't emulating the Logical EOT
*OR* the virtual tape distance between its Logical EOT and Physical EOT
distance is too short - and that within that write, it encountered both
Logical and Physical EOTs. Getting passed the logical EOT doesn't end
ongoing writes. But any write issued AFTER the logical EOT has passed
will incur a UX - this gives the opportunity for any tape writing
software to write end of volume information passed the Logical EOT. If
writing End Of Volume information (because of a Logical EOT) makes VTAPE
run into the Physical EOT then this would happen too.
PS : It's "theorically" possible to correct the problem before the CU
presents the status to the channel.. If the channel is exceptionally
busy and you run VERY fast to your drive, manually rewind it and make it
ready again before the CU has had the opportunity to present the status
because of an ongoing long standing working allegiance condition from
another CU on that channel... Oh well.. I *DID* say it was theorical !
--Ivan
