NFSv2 and v3 server statelesness
NFS server doesn't keep track with what clients access what files.
NFS client keeps track with its RPC calls. If the server doesn't
respond on an RPC call within defined time period, the client repeats the call.
An NFS client receives file handles from NFS server when executes mount and lookup calls.
The file handles on a client relate to the file pointers on an NFS server
(inode number, disk device number, and inode generation number).
If an NFS server crashes or reboots, NFS dependent applications on
the client hang and then continue running after the server becomes available.
If the file system on the server is changed or corrupted, the client
gets a stale file handle error.