IMHO things are different a little bit.
There are several places where the tape is defined, in this case: RMM,
VOLCAT, VTS.
RMM manages the tapes and decide which tape is expired => should become
a scratch tape. VRS, housekeeping, etc.
VOLCAT is just a database, there are no volcat-specific processes like
housekeeping.
Finally the VTS.
VTS definition has two parameters.
The first is number of days before VTS itself destroy (overwrite)
content of the virtual tape volume (*). Let's say it is 10 days.
During the period you can say Ooooops! and quickly recover the tape - it
means change it from scratch to user status. Grace period.
However imagine you have virtual volume number constraint. It such case
when your job request some scratch, the VTS may provide any of the
volumes in grace period - and the volume will be logically overwritten -
which means, no way to change status as above. Data on scratch volume is
lost.
Now the second parameter: Expire Hold (Yes/No). This switch will protect
scratch tape against being mounted for output (and
destroyed/overwritten). Of course it works only for scratch tapes in
grace period.
(*) It is a little bit more complex. "Grace period" means VTS won't
destroy the tape, but after the period is expired VTS may destroy it,
but there is no confidence it will happen immediately. It depends on VTS
cache size, number of tapes, etc. etc.
My humble opinion: Always use Expire Hold, use reasonable number of days
for grace period, adjust it to your environment.
--
Radoslaw Skorupka
Lodz, Poland
W dniu 22.05.2025 o 18:47, Pommier, Rex pisze:
Depending on the VTS, yes. We have TS7770s and they have a user variable where
we can define how long the tape remains on the VTS after being told by z/OS
(OAM) to scratch it before the VTS actually does the scratching.
-----Original Message-----
From: IBM Mainframe Discussion List<IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of
Allan Staller
Sent: Thursday, May 22, 2025 7:57 AM
To:IBM-MAIN@LISTSERV.UA.EDU
Subject: [EXTERNAL] Re: Scratch tape woes (RMM, SMS, OAM)
Classification: Confidential
I know that RMM "keeps" the tape for a day or so (user defined in EDGRMM**),
before marking it available as a scratch. CA-1 does similar.
Perhaps the VTS does something similar internally
-----Original Message-----
From: IBM Mainframe Discussion List<IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of
Vince Getgood
Sent: Thursday, May 22, 2025 3:51 AM
To:IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Scratch tape woes (RMM, SMS, OAM)
[CAUTION: This Email is from outside the Organization. Unless you trust the
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which can steal your Information and compromise your Computer.]
RMM housekeeping hadn't been run in a while, so we've now scheduled it every
night.
I now have 188 scratch tapes (I used a couple yesterday), so the problem seems
to have gone away..
Thanks to all that had posted.
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