how to allocate very big dataset

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how to allocate very big dataset

Postby samb01 » Fri Dec 16, 2011 8:17 pm


i a have a big dataset et i would like to know what is the best kind to allocate the space ?

I don't really know which is the size the final dataset... I juste have five volume (not more...)

Here is the dataset :

                                                                             TRKS   %Used  xt
         XXXXXX.YYYY.ZZZZZZ.AAA                             22500  100     4 
         XXXXXX.YYYY.ZZZZZZ.AAA                             45000  100     2 
         XXXXXX.YYYY.ZZZZZZ.AAA                             45000  100     1 
         XXXXXX.YYYY.ZZZZZZ.AAA                             45000  100     2 
         XXXXXX.YYYY.ZZZZZZ.AAA                            45000  100     2 
***************************** End of Data Set list ****************************

and the allocation is (3000,1500).

The error message is :


Thanks for youy help.
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Re: how to allocate very big dataset

Postby Akatsukami » Fri Dec 16, 2011 8:32 pm

And yet the message referred to an EOV abend on a tape device. Would you care to explain?
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Re: how to allocate very big dataset

Postby Robert Sample » Fri Dec 16, 2011 8:40 pm

Consult your site suport group handling storage management. It may not be possible for your data set to be allocated on 5 volumes. Furthermore, unless you are using a recent version of z/OS and a storage class to allow for large data sets on volumes, specifying (3000,1500) cylinders in your SPACE parameter is useless. If the volumes in question are 3390 mod 3 then 3335 cylinders is their limit, so the secondary could NEVER be allocated. And if the volumes are 3390 mod 9 (or higher), then (3000,1500) would only work when large data set allocation is supported since otherwise the absolute limit for a sequential data set on a disk volume is 65535 tracks or 4359 cylinders.

But the bottom line in all cases like this is to work with your site storage group since they know MUCH more about your environment then we possibly could.
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Re: how to allocate very big dataset

Postby steve-myers » Fri Dec 16, 2011 11:49 pm

Mr. Sample may have missed two important details:
  • Dataset size on one volume.
    As Mr. Sample says, a 3330-3 has just 3335 cylinders. Allocating 3000 cylinders effectively fills the volume; the system cannot allocate 1500 more cylinders on the volume
  • The gory details of allocating a dataset on multiple volumes.
    The same z/OS function, "end of volume," is a catch all routine that handles many different errors. The IEC028I message from an S837-xx ABEND covers a number of codes. Most of the codes are for tape, but 08 is for both disk and tape. Unless you do something in your JCL, you can extend a dataset to 5 volumes. Period. End of story. It doesn't matter whether it's disk or tape. If you expect the dataset will be on more than 5 volumes, you must provide a volume limit in JCL in the VOLUME parameter or specify the volume serials in the VOLUME parameter, or both, as discussed in this link, which evidently you did not review. Of course the volumes must be available. If they are not available, you're done for.
    When you extend the dataset to a new volume, the initial allocation is the secondary allocation, 1500 cylinders in your case, and you can get secondary allocation in the usual way.
This dataset probably should be on real, not virtual, tape, but that's just my horseback opinion. As Mr. Sample says, you really should discuss this with your storage management people, not here.
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Re: how to allocate very big dataset

Postby samb01 » Mon Dec 19, 2011 3:38 pm

I successed with this allocation :


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Re: how to allocate very big dataset

Postby dick scherrer » Tue Dec 20, 2011 1:45 am


And exactly how much space was needed to hold the data? Sounds like the original "Hugeness" of the file was questionable?

Good to hear it is working (and thanks for letting us know :) ), but i'd make sure i understand exactly Why this worked and that there is no surprise at a later date.
Hope this helps,
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Re: how to allocate very big dataset

Postby deemis » Tue Mar 06, 2012 8:10 pm

hi guys,
i need help in space parameter for jcl.
is there any tool or formula available to calculate? for e.g record is 16169902 lrec=339 . so what is space is being used for this. and what are the prmary and secondary space.
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Re: how to allocate very big dataset

Postby prino » Tue Mar 06, 2012 8:19 pm

16169902 / ((27998 div 339) * 339) + 1 tracks

And don't fecking tag on to an existing thread, create a new one!
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