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patnekar · Beginner Joined: 27 Jan 2003 Posts: 41 Topics: 16

Hi,
I need information on how to pre-allocate tapes in a JCL and also the other factors that I should be consider while doing this??

Thanks
Puru

kolusu · Posted: Tue Jan 20, 2004 12:58 pm Post subject:

Patnekar,

The following Jcl will pre-allocate a tape.

Cogito-Ergo-Sum · Posted: Tue Jan 20, 2004 1:52 pm Post subject:

Kolusu,
Why not IEFBR14 with DISP=(NEW,CATLG,DELETE)?
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Debugging tip:
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Bithead · Posted: Tue Jan 20, 2004 1:57 pm Post subject:

I don't think that IEFBR14 sets a valid EOF marker which may, or may not, be a problem.

Cogito-Ergo-Sum · Posted: Tue Jan 20, 2004 2:01 pm Post subject:

Oh, EOF marker. I never quite understood that. Sad

_________________
ALL opinions are welcome.

Debugging tip:
When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.
-- Sherlock Holmes.

kolusu · Posted: Tue Jan 20, 2004 2:01 pm Post subject:

Cogito,

IEFBR14 does not open the dataset for write and a tape dataset cannot be cataloged without opening the dataset. Try to run a sample and see what happens.

Kolusu
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Kolusu
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Cogito-Ergo-Sum · Posted: Tue Jan 20, 2004 2:18 pm Post subject:

Kolusu,
No dataset was allocated! Perhaps, I jumped again! Thanks for the information.
_________________
ALL opinions are welcome.

Debugging tip:
When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.
-- Sherlock Holmes.

patnekar · Beginner Joined: 27 Jan 2003 Posts: 41 Topics: 16

Kolusu,
The need to pre-allocate tapes was felt, as we happened to lose some data, when our tapes were over-written by some other jobs. Thus we felt that if we happen to pre-allocate tapes for our files, we can do away with this over-writting stuff.
Is there any other way of preventing this?? If yes, please let me know.

Thanks
Puru

warp5 · Posted: Thu Jan 22, 2004 1:48 am Post subject:

How are your jobs over-writing tapes? It sounds like you do not have a tape management system or something is very wrong. Tell us the complete story how these over-writes are taking place.

patnekar · Beginner Joined: 27 Jan 2003 Posts: 41 Topics: 16

Warp5,
Sorry but we are still investigating it. In any case I doubt whether I'll be able to post the real reason here, apart from the technical stuff, if any.

Thanks
Puru

Kautilya · Beginner Joined: 24 Jan 2004 Posts: 8 Topics: 2

Use UNIT=(TAPE,2)

slade · Posted: Sun Jan 25, 2004 12:14 pm Post subject:

Hi Puru,

An alternative to pre-allocation may be to use RETPD or EXPDT. These should protect your tapes, provided your "adversaries" don't use BLP when creating theirs.

One drawback though is that using a long period can tie up the tapes and keep other legitamate users from them.

Regards, Jack

zoobink · Beginner Joined: 01 Feb 2004 Posts: 9 Topics: 1

CES Wrote "No dataset was allocated! Perhaps, I jumped again! Thanks for the information."

This happens because IEFBR14 doesn't request an OPEN on the dataset. IEFBR14 is so named because all that it does is BRanch to register 14.

IEBGENER works because a valid OPEN and CLOSE is performed, even though no records are written.