It's a simulated device and I guess 3314 is tiny. I vaguely recall - from more than 25 years ago - wanting to use a tiny one. I think it might be a limit on something - VIO data sets not being multivolume?
(I think this simulation is a significant part of the CPU cost for VIO.) 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/category/mpt/ From: Jesse 1 Robinson <[email protected]> To: [email protected] Date: 11/05/2016 17:05 Subject: Re: Whither VIO? Sent by: IBM Mainframe Discussion List <[email protected]> Mea culpa once again for misstating the facts. My shop does indeed still support VIO--under a different esoteric--but, as Ed Jaffe pointed out, with a pretty severe size limit. I looked through one PROCLIB for instances of VIO. I found it mostly in compile/link jobs with very small work files. As for DFSORT, our default ICEMAC includes VIO=YES, but I have no idea who would use it. In view of our low limit for VIO, I doubt that many SORTWK files would actually end up there. One question I have. In a previous life, we defined VIO (I believe) to device 3314 even though we had none left on the floor. The device type was still valid in IOGEN at that time, and I was told that device architecture was more suitable for VIO than 3380. VIO here is currently defined to 3390. Is there any difference? . . . J.O.Skip Robinson Southern California Edison Company Electric Dragon Team Paddler SHARE MVS Program Co-Manager 323-715-0595 Mobile 626-302-7535 Office [email protected] -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of David Betten Sent: Wednesday, May 11, 2016 8:41 AM To: [email protected] Subject: (External):Re: Whither VIO? When I was in DFSORT, I always recommended not using VIO for sort work data sets. We felt it was better to let DFSORT manage the use of storage for intermediate work space via Hiperspace, Memory Object or Dataspace. One advantage was that DFSORT has controls over the total memory usage by concurrent sort applications. I believe VIO is still something worth exploiting for other types of temporary data sets given the larger storage configurations available today. However, keep in mind that there are also some limitations to VIO such as not supporting large format data sets. Have a nice day, Dave Betten z/OS Performance Specialist Cloud and Systems Performance IBM Corporation email: [email protected] IBM Mainframe Discussion List <[email protected]> wrote on 05/11/2016 11:10:55 AM: > From: Martin Packer <[email protected]> > To: [email protected] > Date: 05/11/2016 11:12 AM > Subject: Re: Whither VIO? > Sent by: IBM Mainframe Discussion List <[email protected]> > > I said in another thread that VIO was one of the worse DIM exploiters > for > CPU usage - in the Orange "Coffee Table" book of DIM studies way back > when. > > I've no reason to doubt it now. I would still expect that for many > uses it > is faster than temporary data sets on disk, though. > > So I would question what we're optimising for. > > And I would agree that a rival implementation - such as hiperspace or > 64-Bit Memory Object sorting - is worth investigating. > > 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/category/mpt/ > > > > From: "Vernooij, CP (ITOPT1) - KLM" <[email protected]> > To: [email protected] > Date: 11/05/2016 15:32 > Subject: Re: Whither VIO? > Sent by: IBM Mainframe Discussion List <[email protected]> > > > > I heard rumors that VIO is that CPU expensive and that I/O is that > fast nowadays, that it is VIO is not worth the extra CPU anymore. > > Therefor I have been thinking about abandoning VIO, but I can't make a > good calculation. I could make the calculation for the SAS WORK file, > which can be in VIO or in HIPERSPACE. The latter is cheaper, as is > stated > by SAS and it is easy to switch to Hiperspace with a simple > installation parameter. > > Does anyone has some figures on other use of VIO? > > Kees. > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] > On Behalf Of Martin Packer > Sent: 11 May, 2016 16:08 > To: [email protected] > Subject: Re: Whither VIO? > > The nasty answer to "what happened to VIO?" is "nothing". :-) :-( > > Seriously, it remains as before but implemented in central storage > rather > than expanded. > > With the improved economics of memory it's worth looking at again - > but only if memory is available to support it. > > 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/category/mpt/ > > > > From: Lizette Koehler <[email protected]> > To: [email protected] > Date: 11/05/2016 14:55 > Subject: Re: Whither VIO? > Sent by: IBM Mainframe Discussion List <[email protected]> > > > > My guess would be: > > DASD is faster > Virtual Tape is faster > Central Memory is plentiful (for some shops) > > Lizette > > > > -----Original Message----- > > From: IBM Mainframe Discussion List > > [mailto:[email protected]] On > > Behalf Of Jerry Callen > > Sent: Wednesday, May 11, 2016 6:51 AM > > To: [email protected] > > Subject: Whither VIO? > > > > In a thread in a distant galaxy, J.O.Skip Robinson wrote: > > > > > ...be aware that some customers (like us) did away with VIO a long > time ago. > > > > I've been away from MVS for a while. Did something better than VIO > > come > along > > while I wasn't looking? Why would VIO have been vaporized? > > > > -- Jerry ---------------------------------------------------------------------- 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
