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High Cpu Utilization on RHEL 5 on zLinux (s390x) (Doc ID 761939.1)

Last updated on AUGUST 31, 2023

Applies to:

Oracle Database - Enterprise Edition - Version and later
Linux on IBM Z
Add *** *** I
BM zSeries Based Linux


When a set of RAC nodes (guests) are active, with only CRS running the vmstat CPU shows around a 3-6% utilisation. the VM Monitor,however, shows 7-14% utilisation of the IFL. This is a twin z10 architecture with a node on each machine, and hence an IFL for each node.

Guests with Single instance Oracle don't even show up in the monitoring software, even though they
are running workloads. This RAC load is consistently the highest utilizer of the IFL - even when


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