Thanks for your analysis and hints. Our default seems to be DYNALOC=N. This is why I tried to overwrite with DYNALLOC=SYSDA. I was hoping that DF-Sort will figure out how many data sets to allocate based on the estimated size. It seems it does not, but instead it allocates either a default number (4) or the number specified via DYNALLOC=. There is a drawback of specifying the number via DYNALLOC=: DF-Sort always allocates this number or work data sets, no matter how much space will be needed.
The job in discussion runs multiple times a day and usually has only a few megabytes to sort, but occasionally there will be a much larger amount of data to work on. If I specify, say DYNALLOC=(SYSDA,100), then there always will be 100 data set allocated by DF-Sort. Will DF-Sort adjust the size of the dynamic allocation based on the estimated size? Is there any other option I could try, or am I stuck to DYNALLOC=(SYSDA,nnn) with a reasonably high "nnn"? -- Peter Hunkeler -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of David Betten Sent: Mittwoch, 3. Oktober 2012 09:59 To: [email protected] Subject: Re: Help with DF-Sort not being able to allocat enough work data set space Based on the record statement and the FILSZ specified, DFSORT estimated it would need 469577MB of disk work space. Your installation default for DYNALOC is probably the shipped default of SYSDA,4. This is going to cause DFSORT to allocate 4 work data sets. The work space allocation will be spread across three of those with one set aside to be used for recovery if the work space requirement is larger than expected. So with such a small number of work data sets, you need to have at least 3 volumes with 156526MB of free space. Since there were not any volumes available with that much free space, your sort failed. On your OPTION statement you might want to change DYNALLOC=SYSDA to DYNALLOC=(SYSDA,30). This would cause DFSORT to spread that 469577MB allocation across 29 work data sets (with 1 set aside). So now you need at least 29 volumes that have 16192MB available. If your storage group has mostly MOD 54s or MOD27s defined, that should be fine. If it has something like a bunch of MOD 9s defined, you'd have to increase DYNALLOC further to spread the work space allocation across more/smaller work data sets. Have a nice day, Dave Betten DFSMS Performance Engineer IBM Corporation email: [email protected] DFSORT/MVSontheweb at http://www.ibm.com/storage/dfsort/ IBM Mainframe Discussion List <[email protected]> wrote on 10/03/2012 03:00:19 AM: ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
