At a prior life at a bank, I ran into a banking application that used dynamic allocation for most of the dataset allocations. We had the TIOT size set to the maximum value. In the SMS data class, we were using the maximum value for the dynamic volume count (I think the value is 59). This caused the dynamic allocations to fail in some of the application's jobs, due to hitting the maximum TIOT size. We had to adjust the SMS DC DVC downward, to get the application to run successfully.
"Confidentially doc, I am the wabbit." Bugs Bunny Sent with Proton Mail secure email. On Wednesday, December 4th, 2024 at 12:28 PM, Lennie Bradshaw <[email protected]> wrote: > Binyamin, > > Thanks for your cryptic hint. On its own not very helpful, but I do know > about how to change the TIOT size at IPL. > > I am well aware that the size of the TIOT affects the number of allocations > that can be performed. But I don't understand how these two limits (TIOT size > and DYNAMNBR) affect the limit on the number of allocations I can have. > > I suspect there is a crucial piece of documentation missing, but I have never > worked it out. > Lennie > > -----Original Message----- > From: IBM Mainframe Discussion List [email protected] On Behalf Of > Binyamin Dissen > > Sent: 04 December 2024 10:48 > To: [email protected] > Subject: Re: DYNAMNBR > > ALLOC** TIOT SIZE > > On Wed, 4 Dec 2024 09:09:10 +0000 Lennie Bradshaw [email protected] > wrote: > > > :>Greetings all, > > :>The JCL Reference manual (SA23-1385-60) states that the DYNAMNBR parameter > can specify a value that is added to the number of existing DD statements for > a job step to produce an upper limit on the number of DD statements that may > be allocated. It also talks about the size of the TIOT and the number of DD > statements it can support and mentions various caveats about the number of > UNITs used, passed data sets, and so on. (It does not discuss the > "permanently allocated" attribute.) > > > :>However it states that the default for DYNAMNBR is zero (0). This would > mean that if no DYNAMNBR is specified that the value used is zero. > > > :>However, this would mean that unless existing DD statements were closed or > freed up in some way, then the number of DD statements I could dynamically > allocate would be, again zero. > > > :>Yet I can use dynamic allocation without specifying DYNAMNBR. How is this > working? Is the JCL Reference wrong? Or is there some piece of this puzzle > that is missing? > > > :>I have looked in several other manuals including the Init and Tuning guide > and the Auth Assembler reference, but cannot see how this is working. > > > -- > Binyamin Dissen [email protected] http://www.dissensoftware.com > > > Director, Dissen Software, Bar & Grill - Israel > > ---------------------------------------------------------------------- > 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 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
