We are seeing a 3x performance improvement when the VM is presented Netapp NFS storage as a guest OS disk vs the VM NFS mounting the same space.
This is problematic in the case where our apache VM pool needs to mount a shared web tree - performance suffers - the shared mounts can not be make "local".
the question is why the 3x performance difference?
Dell 610s 196Gb Ram
vSphere 5.0 U1
Netapp plugin for vCenter provides best NFS settings
CentOS 5 VMs
VM NFS mount options: rw,noatime,bg,nfsvers=3,proto=tcp,hard,nointr,timeo=600,rsize=32768,wsize=32768