DFSORT will adjust the total space allocation as long as the program changes the file size information it passes. However, whatever n value you have for DYNALLOC, is how many work data sets it's going to allocate.
Have a nice day, Dave Betten DFSMS Performance Engineer IBM Corporation email: [email protected] 1-301-240-3809 DFSORT/MVSontheweb at http://www.ibm.com/storage/dfsort/ IBM Mainframe Discussion List <[email protected]> wrote on 10/03/2012 06:27:24 AM: > From: "Hunkeler Peter (KIUP 4)" <[email protected]> > To: [email protected], > Date: 10/03/2012 06:28 AM > Subject: Re: Help with DF-Sort not being able to allocat enough work > data set space > Sent by: IBM Mainframe Discussion List <[email protected]> > > 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 > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
