I've worked for a bank and a wholesaler that both routinely ran at 100%. Service levels were met, but people were always griping about the usage.
As John said, no harm no foul. - -teD - Original Message From: John Eells Sent: Wednesday, May 7, 2014 10:48 To: [email protected] Reply To: IBM Mainframe Discussion List Subject: Re: Mainframe (in general) running at 100% not always a bad thing I'm not sure we have a white paper. Will one of our announcement letters do? "z/OS V2.1 is designed to allow System z servers to run at utilization levels as high as 100%." From http://www-01.ibm.com/common/ssi/ShowDoc.wss?docURL=/common/ssi/rep_ca/8/649/ENUSA13-0568/index.html&lang=en&request_locale=null A Long Time Ago in a Data Center Far, Far Away (well, OK, just down the road from Poughkeepsie in East Fishkill), we used to routinely run at 100% busy during peak times on some systems and for days on end on others. So long as there was enough discretionary work to fill up the box, no harm, no foul. There was even a (WSC?) recommendation at one point (perhaps the MVS/ESA SP Version 3 timeframe) to run BR15s, one per processor, in their own RPGN and in a PGN with very low priority, and subtract that workload from the resulting, constant 100% busy to find out "how busy the system really was." This was a measurement trick to counter some low utilization effects that existed at the time. Customers have told me they routinely run 100% busy at peak times rather more recently. In my opinion this has been a very positive aspect of the platform for a really long time (like 30 years or more!). It's so ingrained we often forget to talk about it...along with a number of other imporant things about which we should perhaps remind people about more often. Chris McGavic wrote: > All, > > I'm trying to find a white paper or something along that line that states > that the mainframe platform (we're on a z/10) can actually run at 100% and > not die as opposed to other platforms. -- John Eells z/OS Technical Marketing IBM Poughkeepsie [email protected] ---------------------------------------------------------------------- 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
