On Wed, Feb 23, 2011 at 12:34 PM, Gregg <reed.gr...@gmail.com> wrote: > I wish I had SAS and I see now where I had an error in my rexx program > re: seconds/ms calc. much closer. my bad sorry. What's BC mode? > z900 or earlier basic mode or 1 LPar/dedicated lCPs?
I believe someone is confused here due to early re-use of acronyms ;-) Long ago, PR/SM was optional, and hardware could be configured to run in "basic mode" versus "LPAR mode" but with current hardware (since z9) it's not optional anymore (unrelated to the z9-BC vs z9-EC difference). This means that on supported hardware, z/VM (or any OS) runs in LPAR, even when that is the only LPAR on the machine. More recently, IBM introduced "IFL-only" models that have no CPs installed and thus don't run "The Operating System" but only z/VM and Linux. Depending on one's context and background, this "without a z/OS LPAR" may be observed as "without an LPAR" - which obviously is not the correct interpretation. PR/SM is the only component to know how much CPU cycles went into LPAR overhead and LPAR management overhead. The z/VM monitor (like RMF) get that information from the hypervisor and pass it along to your favority performance monitor. Any LPAR on that machine would get the same global utilization info from PR/SM (even though MVS does some hide and seek to keep the IFLs out of the total license charges). The z/VM account records do not account for that overhead (no pun intended). The overhead is normally small enough that you could not even tell when you drive all CPUs in a loop and see how far you're away from N*100%. The account records do provide the total for z/VM management overhead (which is different from the LPAR overhead). So if you care to know the LPAR overhead, you need to collect performance data from any one of the partitions on the machine. With ESALPS we feed the data into MXG and MICS, which works well for most installations that do capacity planning. From a license point of view it surely beats the alternative of getting a CP on the machine and run z/OS there just to collect LPAR usage statistics. Rob -- Rob van der Heij Velocity Software http://www.velocitysoftware.com/
