1. NFS Client1 and NFS Client2 mount different NFS servers which are based the same Lustre filesystem.

Topology:

Lustre Server  ->  Lustre Client1(NFS Server1) -> NFS Client1
              ->  Lustre Client2(NFS Server2) -> NFS Client2

2. NFS Client1 create a file by echo "aaa":

# echo aaa > file
# cat file
aaa

3. NFS Client2 read data from the same file:

# cat file
aaa 

4. NFS Client1 update data into the same file:

# echo bbb > file
# cat file
bbb

5. NFS Client2 read stale data from the same file again:

# cat file
aaa