I've been trying to get two hosts to work with a NFS datastore that is running on a Windows 2008 R2 server but I keep running into a problem in which the datastore becomes inactive when any disk activity occurs with a vmdk file. For example, if I try to deploy a vCenter OVF template it starts the process then as soon as it gets to 2-3% it stops and the datastore becomes inactive. If I create a vm on the datastore (which works fine) then try to start a guest OS install then it becomes inactive after about 5-10 minutes. If I try to storage vmotion any vm off of the local storage to the shared storage then this issue occurs but only after several hours of the server trying to move the files. Oddly enough I can copy a 3-4 GB ISO file to the datastore with no problem. Whenever these issues occur the Windows server is still accessible on the network but if I unmount the datastore and try to remount it then it says that it cannot connect. Once the NFS server is rebooted then the datastore is accessible.
I have tried doing these operations from either host and both have the same results. I have disabled any extra features on the NIC used by the NFS server such as TOE to no avail. I have checked the NIC stats on the servers as well as on the switches. There are no errors whatsoever. I have seperated the storage and management traffic so that all NFS traffic uses its own vlan and subnet.