my colleagues are pursuing this with Netapp and Oracle - but I thought I'd post here on the off chance someone else has seen this
We have a RedHat 5 VM (fully up to date) running Oracle 11i with data disks mounted via the VM's linux kernel NFS using Oracle's recommended mount options and the performance is very inconsistent (Querys that should take < 2 seconds sometimes take > 60 seconds)
Funny thing is we can run the same queries perfectly consistently < 2 seconds on a VMDK residing on SAME NetApp NFS datastore!
Makes me wish Oracle and NetApp collaborated as closely as VMware and NetApp did on the Virtual Storage Console we used to perfectly set the NFS options and keep them in compliance...
We have tried a few Linux NFS options others have posted and not seen improvement so far.
We are now creating VMDK's for the VM to replace the Linux NFS mounted and workaround the issue as our developers need consistent performance ASAP.