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SPACE allocation for a new dataset

 
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iknow

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Joined: 22 Aug 2005
Posts: 413
Location: Colarado, US

PostPosted: Fri Nov 04, 2005 6:46 am    Post subject: SPACE allocation for a new dataset
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hi folks
How much SPACE to specify in JCL for a "new" dataset? Explain with an example.
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Kevin

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Joined: 25 Aug 2005
Posts: 234

PostPosted: Fri Nov 04, 2005 7:01 pm    Post subject: Re: SPACE allocation for a new dataset
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Normally, you don't specify space, as the System Managed Storage (SMS) system handles that task.

If. however, you wish to override that, then the answer will depend on your shop's standards. In our shop, space is calculated as follows:

Primary Tracks = (LRECL * MAX # of records) / 56664
Primary Space = (BLKSIZE / LRECL) * 2 * Primary Tracks
Primary Space = Primary Space / 1000

Secondary Tracks = (LRECL * (MAX # of records * .2)) / 56664
Secondary Space = (BLKSIZE / LRECL) * 2 * Secondary Tracks
Secondary Space = Secondary Space / 1000

so, space is allocated like this:
Code:

//         SPACE=(LRECL,(Primary Space,Secondary Space),RLSE),AVGREC=K
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mmwife

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Joined: 30 May 2003
Posts: 1592

PostPosted: Sun Nov 06, 2005 8:28 am    Post subject:
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Hi IK,


You can economize by using BLKSIZE and secondary allocations, but the bottom line is "it depends on how many and how big the recs your new file might be."
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