>>> On Mon, Jun 16, 2008 at 11:48 PM, in message <[EMAIL PROTECTED]>, "Martin, Terry R. (CMS/CTR) (CTR)" <[EMAIL PROTECTED]> wrote: > I saw something in one of the postings that stated that the CPU > utilization numbers that were reported in the z/VM Performance Toolkit > on behalf of a Red Hat 4.6 z/Linux guest were not correct. Is it only > the PTK that does not report the correct numbers or is it any monitor? > Do we know if the numbers reported are bogus on the high side or low > side? I am running z/VM 5.3 and the Linux Kernel is at 2.6.9-67.
No, it's not just Performance Took Kit (with the exception of Velocity Software's products). Any version of Linux for System z prior to SLES10 and RHEL4 didn't have the patches to accurately account for CPU time, and the amount of time the system wasn't being dispatched by the hypervisor (whether z/VM or PR/SM for LPARs). The numbers could vary from being too high, to too low, and could be off by one or more orders of magnitude. Linux kernel version 2.6.9-xx (unless Red Hat back-ported the CPU accounting fixes which I don't think they did) is "vulnerable" to this type of mis-reporting. If you want truly accurate reporting, for pre-SLES10 and pre-RHEL5 systems, Velocity Software is the only viable option you have. Mark Post ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
