I was going to offer that perhaps prior to 2.2 the UIC started at 64K-1 and now it doesn't. They key word being "perhaps".
I suppose I have data around to test that conjecture - but I can't remember a data set where an IPL happened. Cheers, Martin Martin Packer, zChampion, Principal Systems Investigator, Worldwide Cloud & Systems Performance, IBM +44-7802-245-584 email: [email protected] Twitter / Facebook IDs: MartinPacker Blog: https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker Podcast Series (With Marna Walle): https://developer.ibm.com/tv/mpt/ or https://itunes.apple.com/gb/podcast/mainframe-performance-topics/id1127943573?mt=2 From: "Feller, Paul" <[email protected]> To: [email protected] Date: 22/08/2016 14:20 Subject: Re: Low UIC count on z/OS 2.2 Sent by: IBM Mainframe Discussion List <[email protected]> As far as I know a low UIC count right after an IPL is normal. I don't have a z/OS 1.13 system, but on our z/OS 2.1 and z/OS 2.2 systems do show a low UIC count after an IPL. The count gets higher over time. I think this is just the nature of the UIC. Thanks.. Paul Feller AGT Mainframe Technical Support -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Jaco Kruger Sent: Monday, August 22, 2016 07:43 To: [email protected] Subject: Low UIC count on z/OS 2.2 Good day, We are preparing to migrate from z/OS 1.13 to z/OS 2.2. The TST LPAR has 8GB Central Storage assigned and it resides on IBM z13. On z/OS 1.13, the UIC count is 65535 during and after the IPL. On z/OS 2.2, the UIC count is below 1000 during the IPL and it gradually increases. The Central Storage have been increased to 50GB on the TST LPAR, but the UIC count during the IPL stays below 1000, even when only basic components are started. There is no PAGING to Auxiliary storage. HVCOMMON, HVSHARE are DEFAULT values. LFAREA is set to 0M The WSET and Memory Object sizes (as obtained from RMF) have been compared between z/OS 1.13 and z/OS 2.2 and there are no candidates that justifies the low UIC count. Any idea on how to determine the reason for the low UIC count ? Regards Jaco Kruger ---------------------------------------------------------------------- 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 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
