The DYNAMNBR parameter is used to indicate how many Task I/O Table (TIOT) slots to reserve for data sets that may be dynamically allocated during the job step.
The TIOT contains control blocks for every DD allocated in your jobstep ( dynamically or via JCL ) . If you fill the TIOT, no more files may be allocated until some are unallocated. TIOT size varies based on operating system settings. The Dynamnbr tells the system how many data set allocations to hold in anticipation of reuse. (The system actually holds n plus the total number of the DD statements used by the step.) Does that help? Lizette -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Paul Gilmartin Sent: Thursday, January 15, 2015 7:47 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: IKJ56220I max # of datasets reached On Wed, 14 Jan 2015 22:11:35 -0500, Shmuel Metz (Seymour J.) wrote: > >>But, ISTR reading long ago that DYNAMNBR is policed by the TSO >>ALLOCATE command and that BPXWDYN is exempt from the limit. > >The ALLOCATE command is jusy another customer of DYNALLOC and it would >make no sense to put a restriction there. Most allocations are done via >DAIR or directly via DYNALLOC. > Now, I don't understand. I just tried: //STEP EXEC PGM=IKJEFT01,DYNAMNBR=10 ... with the EXEC: /* Rexx main program. */ trace C do I = 1 to 11 address 'TSO' 'allocate dsn(TEST'I') new delete' if RC<>0 then leave I; end do J = 1 to 11 RC = BPXWDYN( 'alloc DSN('userid()'.TEST'J') new delete' , 'rtddn(D) msg(WTP)' ) if RC<>0 then leave J say 'Allocated' D; end J exit( RC ) ... it successfully allocated 22 data sets. AFAIK, 22 is greater than 10. What's happening here? -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
