So the DVC sets up the TIOT storage needed Allocation builds the task input/output table (TIOT), which provides a link between a data set and the volumes it exists on. The TIOT entries contain the name of each DD statement and pointers, four bytes long, to the unit control blocks (UCBs) of the associated devices. By decreasing the DYNVOL count in the DATACLAS, less TIOT and TCTIOT space will be consumed by data set allocations. By increasing the TIOT size via the ALLOCxx parmlib member TIOT SIZE parameter, additional storage is reserved for TIOT entries.
This apar has a nice write up of Dynamic Volume Count. http://www-01.ibm.com/support/docview.wss?uid=isg3T1000065 Lizette -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Dean Montevago Sent: Sunday, January 04, 2015 7:35 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: what is the diffenet between volcount and Dynamic Volume Count Using volcount creates the UCB entries in the catalog at allocation taking up space in the catalog upfront, where DVC creates the UCB as an additional volume is needed. I set volcount to 1 and specify a value for DVC, and have not had any issues. I too am looking for the reason why you would choose volcount over DVC. On Sun, Jan 4, 2015 at 2:08 AM, ibmmain <ibmm...@foxmail.com> wrote: > Hi all > > Could you explain what is the diffenet between volcount and Dynamic > Volume Count ? > > I am very confused how to use volcount and Dynamic Volume Count > > Thanks a lot! > > Best Regards, > > Jason Cai > -- Dean Montevago ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
