Spann, Elizebeth (Betsie) wrote:
Hi, How is the st value displayed in the 2.6 kernel version of vmstat computed in general terms? I've seen it described as time stolen from a virtual machine.
Steal time is the percentage of time a virtual CPU waits for a real CPU while the hypervisor (in this case, z/VM) is servicing another virtual processor.
Are there differences between the value on a RHEL 5.0 system vs a RHEL 5.2 system? I've seen references to it being "fixed". ??
The RHEL5.x series (and SLES10 onwards) should all behave in the same manner. This wasn't a Red Hat vs Novell fix, it was a feature added to the kernel which we both incorporated into our distributions. Previously the kernel would use tick-based CPU accounting (versus virtual CPU time). The numbers based on tick-based CPU time accounting report CPU times spent in a /virtual/ CPU context, versus times spent in a /real/ CPU context.
Is the vmstat value similar to the mpstat value?
Yes, but the accuracy is different. mpstat will extend into the 100th of a percent. Example: # mpstat %sys 4.17 %idle 68.21 #vmstat sys 4 id 68 Do note that vmstat does *not* count itself as a running process -Shawn ---------------------------------------------------------------------- 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
