On Thu, 19 Oct 2006 13:03:34 -0400, David Betten <[EMAIL PROTECTED]> wrote:
>See my answers below: > > >>We had a very large DFSort job that abended because of insufficient >>Sortwk space with message ICE083A, indicating that 4 times 65535 tracks >>were not enough. > >I'm guessing your system is not a z/OS 1.7 yet. Just an fyi that for >systems at 1.7 or later, DFSORT allocates the sortworks as large format >so they can exceed 65535 tracks (providing there are volumes with that >much space available). > >>Looking for options to raise the default of 4 Sortwk's, I ran into 2 >>questions to which I could not find the answer: > > > >>1. I cannot find any recommandations in the DFSort manuals about >>the optimum number of Sortwk's. > >>2. From the manual I understood that the number of Sortwk's that I >>specify in the DYNALOC parameter of the ICEMAC macro's specified the >>*maximum* number of Sortwk's DFSort was allowed to take and that it does >>not force dymanic allocation, nor the number of Sortwk's. >DFSORT will almost always allocate the number of sortworks you specify in >the DYNALOC (installation default) or DYNALLOC (runtime specified). >However, if you have JCL sortworks coded but DYNAUTO=IGNWKDD >is not in effect, then it will use the JCL sortworks and not perform >dynamic allocation. When dynamic allocation is used, the sortwork space >required is spread across all the sortworks. So more sortworks does not >mean >more space, but instead it means more/smaller sortwork datasets. > >I'm sorry if our manuals are unclear and will see if we can revise to make >it more clear. I'll add that to the list of things to consider >for future releases. > > David, thanks for the clarifications. Yes, we are at 1.6. I noticed that allocating a large number of sortwk's can take a considerably long time, so I think I will leave the TSO defaults at 4 and raise the JCL defaults to 10. The abending job was sorting a 16 GB DB2 table space, so this will raise the new limit well above that size. I appreciate that you add a few lines of recommandation about the number of sortwk's to the tuning manual. Thanks, Kees. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
