Our VMware ESX 3.5 servers RHEL5.4 NFS datastores are running very slowly. We have spent a significant amount of time to find that its the ESX host that is specifically having performance problems writing to this NFS datastore. We found that by enabling async on the NFS export we were able to get the expected throughput for our configuration. I saw a VMware knowledge base article that strongly recommends against using async, and I've also read all of the implications that comes with its use.
My question for everyone is has anyone successfully configured RHEL5 NFS for use as a datastore with realistic usable performance speeds (without using async). We already have our equipment and were not in a position to migrate over to a Netapp solution. I saw somewhere where it might be possible to use async on the client side for NFS? Would that cause the same data integrity write problems, and is it possible to modify the vmkernel nfs mount options.
We know how to do iSCSI, we are just trying to solve the NFS problem for our partners configuration.