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yuva_chowdary
New User
Joined: 07 Feb 2009
Posts: 4
Location: India
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Hi,
I wish i could have some information on the utility: SAMUTIL, which i referred in one of the JCL used to extract a file from TAPE into Flat file. I would like to know how this works.
One more question: Do any one have a JCL in place, which extracts a file on TAPE into some flat file? It would be really helpful if some one can share that.
Thanks in advance !!!!!!!!
Yuva. |
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enrico-sorichetti
Superior Member
Joined: 14 Mar 2007
Posts: 10886
Location: italy
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SAMUTIL is not part of any zOS vanilla distribution/installation
the best thing to do is to ask Your peers |
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Robert Sample
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Joined: 06 Jun 2008
Posts: 8700
Location: Dubuque, Iowa, USA
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Depending upon how the tape file was built, IEBGENER, IEBUPDTE, or DF/DSS (ADRDSSU) may be required to dump the tape into a flat file. Assuming the data on tape was copied from a flat file, a standard IEBGENER (see the Utilities manual -- link at the top of the page -- for the JCL statements needed) will do the trick.
Since tape device names are site specific, you don't really want to attempt to run JCL from another site to unload the tape. Use the manual example, find out the tape device name from your coworkers or team leader, and proceed from there. |
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Craq Giegerich
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Joined: 19 May 2007
Posts: 1512
Location: Virginia, USA
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SAMUTIL sounds like a site specific program.
How are these tapes created? |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006
Posts: 19243
Location: Inside the Matrix
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Hello and welcome to the forum,
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| How are these tapes created? |
If you do not know how the tapes were created, find the job(s) that created them to learn how they were created. |
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yuva_chowdary
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Joined: 07 Feb 2009
Posts: 4
Location: India
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| thank you seniors !!!!!! |
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Anuj Dhawan
Superior Member
Joined: 22 Apr 2006
Posts: 6248
Location: Mumbai, India
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Hey Dick -- that was a question from Criag.. (just being litle picky today).
Robert -- I always thought (and found, in the realm of application engineer) that tape files are, essentially, sequential files because they can be accessed in sequential manner only. Now when i read this,
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| that Assuming the data on tape was copied from a flat file |
(my concern is about bold text)1. What other source you are talking about to copy from? 2. And does that really make a difference? I mean, tapes, anyways, will be accessed sequentially(Actuators have no other option than reading in sequential manner, right?)? Or did I percept the bold text in an incorrect manner (probably)... |
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Robert Sample
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Joined: 06 Jun 2008
Posts: 8700
Location: Dubuque, Iowa, USA
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Anuj: yes, tapes are sequential files. However, if a PDS was unloaded to tape using IEBCOPY, the file layout, while sequential, really rquires IEBCOPY to put it back together. For example, the tape RECFM will be VB (no matter what the PDS is) and the LRECL will be 20 (or 16? don't have manual available right now to check) bytes more than the PDS block size. Another example is DF/DSS output -- it's on a tape, so it is sequential. However, the file on tape cannot be copied without data corruption (except by DF/DSS).
People say tape, they think data file -- but the data on tape may be a straight copy of a file, an unloaded PDS, or a DF/DSS backup (just to name a few) and it is imperative to know what built the tape to be able to retrieve the data on it successfully. |
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Anuj Dhawan
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Joined: 22 Apr 2006
Posts: 6248
Location: Mumbai, India
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Thanks Robert, that helps.  |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006
Posts: 19243
Location: Inside the Matrix
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Hi Anuj,
Yup, Craig asked the question, but it appeared that TS did not know the origin of the tape(s).
Also, there are many "sequential" files that are are not "flat files" as almost every proprietary dasd format can be backed up to tape - using some standard utility or some product specific process. |
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Anuj Dhawan
Superior Member
Joined: 22 Apr 2006
Posts: 6248
Location: Mumbai, India
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Hi Dick,
I got yor point now about that "quote"... 
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| Also, there are many "sequential" files that are are not "flat files" |
Did you mean, there are files which can be accessed sequentially but they are not QSAM? 'am little unsure about above statement, please assist. |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006
Posts: 19243
Location: Inside the Matrix
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Hi Anuj,
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| Did you mean, there are files which can be accessed sequentially but they are not QSAM? |
No - when they are on tape they are read as qsam (to restore, primarily), but should not be confused with standard sequential data.
Only code that knows the "backup format" rules can be used to work with this type of data.
This type of data is basically never written/read by business application code. |
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Anuj Dhawan
Superior Member
Joined: 22 Apr 2006
Posts: 6248
Location: Mumbai, India
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Thanks Dick . . .
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| This type of data is basically never written/read by business application code. |
We, The Poor Appilcation Engineers... 
PS. Please don't go by my words and corresponding expressions -- they just don't complement each other... |
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