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patnekar Beginner
Joined: 27 Jan 2003 Posts: 41 Topics: 16
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Posted: Tue Jan 20, 2004 12:31 pm Post subject: How to preallocate tapes ?? |
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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 |
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kolusu Site Admin
Joined: 26 Nov 2002 Posts: 12369 Topics: 75 Location: San Jose
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Posted: Tue Jan 20, 2004 12:58 pm Post subject: |
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Patnekar,
The following Jcl will pre-allocate a tape.
Code: |
//STEP0100 EXEC PGM=IEBGENER
//SYSPRINT DD SYSOUT=*
//SYSUT1 DD DUMMY,
// DCB=(LRECL=80,RECFM=FB,BLKSIZE=0)
//SYSUT2 DD DSN=YOUR TAPE OUTPUT DSN,
// DISP=(NEW,CATLG,DELETE),
// UNIT=TAPE,
// VOL=(,RETAIN,,10),
// DCB=(LRECL=80,RECFM=FB,BLKSIZE=0)
//SYSIN DD DUMMY
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Can you clarify as to why you want to pre-allocate a tape dataset?
Thanks,
Kolusu _________________ Kolusu
www.linkedin.com/in/kolusu |
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Cogito-Ergo-Sum Advanced
Joined: 15 Dec 2002 Posts: 637 Topics: 43 Location: Bengaluru, INDIA
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Posted: Tue Jan 20, 2004 1:52 pm Post subject: |
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Kolusu,
Why not IEFBR14 with DISP=(NEW,CATLG,DELETE)? _________________ 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. |
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Bithead Advanced
Joined: 03 Jan 2003 Posts: 550 Topics: 23 Location: Michigan, USA
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Posted: Tue Jan 20, 2004 1:57 pm Post subject: |
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I don't think that IEFBR14 sets a valid EOF marker which may, or may not, be a problem. |
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Cogito-Ergo-Sum Advanced
Joined: 15 Dec 2002 Posts: 637 Topics: 43 Location: Bengaluru, INDIA
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Posted: Tue Jan 20, 2004 2:01 pm Post subject: |
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Oh, EOF marker. I never quite understood that. _________________ 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. |
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kolusu Site Admin
Joined: 26 Nov 2002 Posts: 12369 Topics: 75 Location: San Jose
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Posted: Tue Jan 20, 2004 2:01 pm Post subject: |
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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 _________________ Kolusu
www.linkedin.com/in/kolusu |
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Cogito-Ergo-Sum Advanced
Joined: 15 Dec 2002 Posts: 637 Topics: 43 Location: Bengaluru, INDIA
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Posted: Tue Jan 20, 2004 2:18 pm Post subject: |
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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. |
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patnekar Beginner
Joined: 27 Jan 2003 Posts: 41 Topics: 16
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Posted: Wed Jan 21, 2004 9:15 am Post subject: |
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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 |
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warp5 Intermediate
Joined: 02 Dec 2002 Posts: 429 Topics: 18 Location: Germany
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Posted: Thu Jan 22, 2004 1:48 am Post subject: |
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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. |
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patnekar Beginner
Joined: 27 Jan 2003 Posts: 41 Topics: 16
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Posted: Thu Jan 22, 2004 2:39 pm Post subject: |
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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 |
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Kautilya Beginner
Joined: 24 Jan 2004 Posts: 8 Topics: 2
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Posted: Sat Jan 24, 2004 3:55 am Post subject: |
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Use UNIT=(TAPE,2) |
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slade Intermediate
Joined: 07 Feb 2003 Posts: 266 Topics: 1 Location: Edison, NJ USA
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Posted: Sun Jan 25, 2004 12:14 pm Post subject: |
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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 |
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zoobink Beginner
Joined: 01 Feb 2004 Posts: 9 Topics: 1
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Posted: Mon Feb 02, 2004 5:15 am Post subject: |
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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. |
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