NetApp NFS filer closing and resetting NFS connections

Issue

• We have a nfs performance issue on some RH5.9 servers: running commands is slow eg: df. NFS exports are on a Netapp filer and are exported with autofs map which are used with NIS. There was no issue yesterday nor a change on the Netapp configuration. When running nfsiostat we see a high retransmission rate on the exported shares.