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pdjorg
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Contributor

Oracle 11g Performance Issue with vCNS

Hello all.

My team is doing a PeopleSoft Financials implementation, deployed on vSphere 5.5 on a FlexPod (Cisco UCS blades with NetApp storage).

The database in this deployment is Oracle 11g running on Red Hat Enterprise Linux 6.5 inside a vSphere VM. The RHEL VM has some local VMDK file systems for the system volumes, but the Oracle database is running over guest-mounted NFS. We also added a second vNIC to this database VM so that these Oracle NFS volumes could be mounted over a Jumbo Frames-enabled network path for performance; the filer and this vNIC are on the same Layer 2 segment, so there is no router in the picture. Jumbo Frames is enabled throughout the path (guest OS, vSwitch, UCS vNIC, physical Nexus switch, and NetApp LIF are all properly configured).

We have vCNS installed and inspecting traffic for the database and all the other VMs in the application (web and app tiers). We presently do not have any deny rules in vCNS; the handful of rules (less than 10) that have been implemented are "allow" rules, and the final default rule is also "allow", so vCNS is not dropping anything by policy.

Performance was initially disappointing, and after some trial and error I discovered that performance improves dramatically if the database VM is excluded from vCNS protection in vShield Manager. The issue is definitely vCNS, as we can consistently reproduce the problems by returning the database server to vCNS protection, and the issues immediately disappear and performance returns to acceptable levels as soon as the database server is again excluded from vCNS protection.

I would like to run a test by excluding only the second vNIC that is used for Jumbo Frames NFS traffic for the Oracle database, but there does not appear to be any way to do that.

My suspicion is that somewhere along the way some kind of latency is being introduced that Oracle is unhappy with, thus the performance impact. My DBA tells me that Oracle Enterprise Manager does complain that I/O throughput "could be better" (his words) while vCNS is enabled.

Has anyone else ever seen Oracle over NFS deployed with vCNS protection? If so, did you have to do anything special to get acceptable results?

Message was edited for legibility by: pdjorg

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