On Wed, 10 Oct 2007 23:04:24 +0000, Ted MacNEIL <[EMAIL PROTECTED]> wrote:
>>I thought the rule of thumb for Logical to Physical CPU's was a 2:1 ratio. > >As always, it depends. >The CP:LP ratio is dependent on the activity of the LPARs. NOT on the number of LP's. > >I've gone 3:1 with low activity images. We've used 4:1 (or higher) on our "penalty box"... All in the archives.... The old ROT was 2:1 and basically still applies. It is also still documented in the RMF Performance Management guide (Appendix A). I remember seeing something about 3:1 in some z990 white paper, but it may have been an IBM "internal use". The best advise is not to define more than you need to do the work. Bottom line... if it works and performance is acceptable, it's ok. If you have a z9 with 2 processors and have 5 LPARs all with 2 LPs, (5:1 ratio), whats the harm if the box never hits capacity (some people are not comfortable defining an LPAR with only 1 CP). Look on the techdocs website for a white paper about performance considerations when moving to fewer faster CPUs. IIRC, there is a benchmark in done in there comparing CICS and batch response times between a 9672 and a z900 with a 10:1 LP/CP ratio (the z900 was better). A little dated.. but think of how much faster a z9 engine is than a z900! HTH, 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 and OS390 expert at http://searchDataCenter.com/ateExperts/ 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
