Hi everybody, In a presentation at GSE I saw a slide with a graph about the advantage of having more small sysplex LPARs versus a bigger one. So for instance, it's better to have 5 LPARs with 4 processors than one with 20.
There was a sentence: "It doesn't take an extremely large number of CPUs before a single-image system will deliver less capacity than a sysplex configuration of two systems, each with half as many CPUs". And: "In contrast to a multiprocessor, sysplex scaling is near linear. Adding another system to the sysplex may give you more effective capacity than adding another CP to an existing system." We've been told (IBM Labs, it seems) that a 4 ways DataSharing with 8 CPUs perform 20% better than a single LPARs with 32 CPUs. The same (at another customer site) with "having more than 8 CPUs in a single LPAR is counterproductive". Putting these infos all together, it seems it's better to have more small partitions (how small ???) in data sharing than, let me say, four bigger ones (in data sharing too). Anybody there has direct experience on doing and measuring such scenarios ? Mainly standard CICS/Batch/DB2 application. Of course I'm talking about well defined LPARs with High Polarization CPUs, so don't think about that. Could you imagine and share your thoughts (direct experiences would be better) about where the inefficiency comes from ? Excluding HW issues (Polarization and so on), could it come from zOS related inefficiency (WLM queue management) ? If so, do zIIP CPUs participate in inefficiency growth ? I know that the usual response is "it depends", anyway I'm looking for general guidelines that allow me to choose. Thanks a lot in advance for your valuable time. Max <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Privo di virus.www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
