On Sat, 6 Sep 2008 12:09:46 -0700, Ron Hawkins <[EMAIL PROTECTED]> wrote:
>Mark, > >I converted SYSVTOC, SYSVVDS and SYSIGGV2 on a three way MAS back when we >were still on parallel channels. The MIM file was on 3880-23 and really >loved that cache, but the benefits were substantial, especially during the >batch run hardware reserves on VTOCs and catalogs were a major pain. >Converting SYSIGGV2 was to solve some soft embrace issues we were hitting. > Ron, SYSIGGV2 is being converted. You have to or you will run into deadly embraces as you already saw. This has been documented since MVS/ESA. >Did the same thing on a two way MAS a few years later at two sites that also >had a lot of the same contention. One with GRS and the other with MIM using >the Turbo option. This was on ESCON and the benefits were noticeable but not >as substantial. > >I would think that converting these three Reserves would be one of the first >things you do if you go MIM or GRS, Star or ring. While they are very high >in the overall count of reserves, the rate is actually quite low. 1,000,000 >reserves in day is only 11 per second. I would think twice before doing this >beyond three systems in a GRS ring though. > >Ron As I said I have 8 systems involved. I would never consider it with GRS RING, but MIM works more like a star configuration the way data is passed around the MIMplex. And I agree that not all reserves are the same - some are much more expensive than others. I see about 50,000,000 for SYSZVVDS on one of the busiest LPARs in this MIMplex and that system was IPLed last weekend. I indicated in a planning meeting that I suspect we could live with converting those resources but I still want to be cautious and only turn them on for 1 evening and see what happens. And then only if I have to (we may not require the use of LDMF at all since this particular environment has 1-2 scheduled outages a month). But just to illustrate that you can't just start changing reserves to ENQs at will in an environment that is not GRS STAR (or MIM in a CF), we once changed the STK resource name that controls access to their CDS for HSC and VTCS. Virtual tape processing didn't come to a halt but things really backed up and batch fell hours behind before I figured out what was going on. This was in this same environment (8 systems in the MIMplex across 2 sysplexes). Regards, Mark -- Mark Zelden Sr. Software and Systems Architect - z/OS Team Lead Zurich North America / Farmers Insurance Group - ZFUS G-ITO mailto:[EMAIL PROTECTED] z/OS Systems Programming expert at http://expertanswercenter.techtarget.com/ Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
