High Cpu Utilization on RHEL 5 on zLinux (s390x)

(Doc ID 761939.1)

Last updated on APRIL 24, 2017

Applies to:

Oracle Server - Enterprise Edition - Version: and later   [Release: 10.2 and later ]
IBM: Linux on System z
Add ***Checked for relevance on 27-Dec-2010*** 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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