Which version of NFS is my NFS server using?
The nfsstat -c
program will show you the NFS version actually being used.
If you run rpcinfo -p {server}
you will see all the versions of all the RPC programs that the server supports. On my system I get this output:
$ rpcinfo -p localhost
program vers proto port
100000 2 tcp 111 portmapper
100000 2 udp 111 portmapper
...
100003 2 tcp 2049 nfs
100003 3 tcp 2049 nfs
100003 4 tcp 2049 nfs
100003 2 udp 2049 nfs
100003 3 udp 2049 nfs
100003 4 udp 2049 nfs
...
This shows me that my NFS server (localhost
in this example) offers versions 2, 3, and 4 of the NFS protocol all over UDP and TCP.
Depending your OS and version there may be different ways to check it.
nfsstat:
# nfsstat -m
/mnt/share from 10.0.0.1:/mnt/share
Flags: rw,relatime,vers=3,rsize=524288,wsize=524288,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.0.0.1,mountvers=3,mountport=30924,mountproto=udp,local_lock=none,addr=10.0.0.1
But you can for sure
# grep nfs /proc/mounts
10.0.0.1:/mnt/share /mnt/share nfs rw,relatime,vers=3,rsize=524288,wsize=524288,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.0.0.1,mountvers=3,mountport=30924,mountproto=udp,local_lock=none,addr=10.0.0.1
which is obviously the same output.
It shows vers=3
on server, and mountvers=3
.