Stephen,
If you Enable the Clear_Tdisk feature, all system T-disk space is
cleared at IPL time the entire T-disk is cleared when it's detached, and
if you attach a new T-disk volume to SYSTEM, all space on that volume is
cleared. Turn on the feature, IPL, then detach one of your T-disk
volumes from SYSTEM and reattach it. Immediately enter Q ALLOC TDISK
and you'll see that all space is in use. Issue it a few times over the
next minute or two, and you'll see the space free up as it's cleared.
Dennis O'Brien
My computer beat me at chess, but it was no match for me in kickboxing.
From: The IBM z/VM Operating System [mailto:ib...@listserv.uark.edu] On
Behalf Of Gentry, Stephen
Sent: Wednesday, September 16, 2009 14:10
To: IBMVM@LISTSERV.UARK.EDU
Subject: [IBMVM] TDISK and SYSTEM CONFIG question.
There is an option in the SYSTEM CONFIG file to clear the T-DISK. It is
in the FEATURES list and CLEAR_TDISK can be either ENABLED or DISABLED.
The manual states that it clears only cylinder 0 (zero) or the first
eight blocks on the temporary minidisk when it detaches the minidisk. Do
they mean the minidisk that is created with the DEFINE statement or is
it the T-DISK area that gets cylinder 0 or first 8 blocks cleared?
Further, and in the same manual, it states that you can clear each
T-DISK before it is reassigned. It depends on your point of view but
this seems contradictory. Clear, in my opinion, means the T-DISK created
with the DEFINE command is completely cleared. Of course clearing
cylinder 0, in effect, makes the area unreadable. Also one section of
the manual seems to say that the area is cleared at IPL time, the other
section seems to say it is cleared before it is reassigned.
I'm not trying to point out discrepancies in the manual, I'm curious as
to why it was originally needed and when does it actually get cleared.
(An external auditor is really hung up on this area not being cleared.)
Thanks,
Steve
