9 Aug
2015
9 Aug
'15
5:57 p.m.
On 08/09/2015 03:03 PM, Jay Jaeger wrote:
No, the OS did the drive assignments, and then
prompted the operator
to do the mount of the appropriate VolSer on a given drive. The
label was of course checked as part of the OS/360 open process, and
if there was a label, and it was not expired, one could not write
over it, or, whether reading or writing, that the label matched the
requested DSN.
(Remember that OS/360 never heard of the 3480 tapes and their
autoloaders - things presumably changed then, along with tape
library management software, but by then I had moved on from
mainframes, and what little I did with them didn't involve tape).
The operators I worked with almost never mismounted a tape.
I'd pretty much left the 360 world after DOS/360 (that really dates me),
so I couldn't comment--except that I never trusted an operator to mount
tapes, if I could do anything about it. A lot of the tapes came from
customers who supplied them to demonstrate a problem. Losing one meant
a lot of apologies and begging.
Much of my big-iron days were spent in operating system work, so I
needed the machine all to myself in any case---you know,
middle-of-the-night block time, after the CEs were through. Build a
tape, deadstart it, watch the machine crash, get a dump, punch some
cards, lather, rinse, repeat. Come home to grab a shower and dinner and
be back in time for the 9AM status meeting.
Those years have affected my sleep habits all the way to my "golden
years". They didn't do much for my social life either.
--Chuck