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Re: RETPD Parameters in DASD File

PostPosted: Wed Oct 02, 2019 8:34 pm
by samb01
Hello, it is not for all the jopb's' production.
Only few job that runs several times a day.

And each time the job run, a tape in created to backup his own datasets.

To answer to steve-myers, yes we have Virtual Tapes but the number of tapes is important. The less the tape we use, the less VTS abd CA1 have to manage.
I think it's not a good idea to have a huge number of virtual tape. And there a limit about the range define in the ROBOT.

Re: RETPD Parameters in DASD File

PostPosted: Fri Oct 04, 2019 1:38 am
by steve-myers
samb01 wrote:Hello, it is not for all the jopb's' production.
Only few job that runs several times a day.

And each time the job run, a tape in created to backup his own datasets.

To answer to steve-myers, yes we have Virtual Tapes but the number of tapes is important. The less the tape we use, the less VTS abd CA1 have to manage.
I think it's not a good idea to have a huge number of virtual tape. And there a limit about the range define in the ROBOT.

I'd guess it's been 40 years since I've been directly involved with CA1. I don't understand the concern about many tapes, as long as they are recycled back to the scratch pool on a regular basis. It makes some real work for the tape librarians, but not really all that much.

Similarly, I don't understand your concern about a "large" number of virtual tape volumes, so long as they get recycled back to the virtual scratch pool. That's the nice thing about "virtual;" you only have to worry about the workload of "virtual" librarians!

Re: RETPD Parameters in DASD File

PostPosted: Fri Oct 04, 2019 5:39 pm
by samb01
Hello steve-myers.
It's really instersting what you told.
May be it's a "wrong" problem i try to solve.
I want to save tapes by using dasd dataset. Maybe it's unusefull.
It was usefull when the tape were not virtual ?
Actually, we have 143096 scratch tapes.
Our cache is used at 77% ( 459 To / 596 To)

Sorry i can't anderstand when you talk about workload of "virtual" librarians ?