On Fri, 25 Mar 2022 13:04:37 +0000, Allan Staller <[email protected]> wrote:

>Classification: Confidential
>
>The last time I  looked, DF/SORT required single extent SORTWK. SYNCSORT did 
>not.
>
>I suspect that SORTWKxx overrode SMS.
>
>-----Origilal Message-----
>From: IBM Mainframe Discussion List <[email protected]> On Behalf Of 
>Paul Gilmartin
>Sent: Thursday, March 24, 2022 3:40 PM
>To: [email protected]
>Subject: Re: Can SORTWKnn Data Sets Use More Than One Volume?
>
>[CAUTION: This Email is from outside the Organization. Unless you trust the 
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>
>On Thu, 24 Mar 2022 19:49:24 +0000, Michael Watkins wrote:
>
>>    ... A quick search of the IBM documentation doesn't seem to provide a 
>> conclusive answer. Anyone got a clue?
>>
>I'm confident you'll get a knowledgeable answer.
>
>I wonder, which is better:
>o More single-volume data sets for greater I/O overlap?
>o Fewer multi-volume data sets using less buffer space?
>
>SORT knows best; let it choose.
>
>Or using only 64-bit virtual for woskspace?  The technique should be designed 
>with LoR to optimize paging.
>
>Do virtual disks do anticipatory resds?
>
>Is bus bandwidth saturation a concern?
>
>--
>gil
>

DFSORT and SYNCSORT SORT-WORK (JCL DD type) allocations take secondary extents, 
but limited to 16 total (z/OS MVS legacy restriction - single-volume) and also 
only up to 65,535 total tracks (on a single volume), unless DSNTYPE=LARGE is 
specified (either DD parameter or DATACLAS) - if host SORT utility performs 
allocation, then DSNTYPE=LARGE is automatically used.  
No TAPE-directed SORT-WORK allocations supported either, and while VIO is 
permitted, it appears to be discouraged, due to increased CPU-time, for that 
matter.  Instead, consider opportunity to ensure that ICEPRMxx settings (also, 
run-time overrides via DFSORT's SORTCNTL/DFSPARM or $ORTPARM for SYNCSORT) are 
tuned to the current z/OS environment, in particular associated with memory 
object usage.

Scott Barry
SBBTech LLC

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