Before mounting an NFS share, can the NFS client know if it's NFS v3 or v4?

Question

The mount command in linux requires -t nfs4 in order to mount version 4 NFS shares, so I need to know beforehand which version it is.

Answer 1

Per: NFS version 3 and 4 with TCP/IP protocols, you could enter either of these commands:

rpcinfo -p <hostname> |grep nfs

rpcinfo -s <hostname> |grep nfs 

Note: All flavours of the command appear to support the -p argument, while the Solaris and GNU linux variants also support the -s variant.

You could include some logic, based around the enquiry, into a shell script that instantiates a variable that could be pluged into a mount command e.g.

nfsHost="11.22.33.44"
ARRAY=`rpcinfo -p $nfsHost |grep nfs |sed -e "s/ [\s ]*/ /g" -e "s/^ //" |cut -f2 -d" "`
Ver=0
for i in $ARRAY ; do if [ "$i" -gt $Ver ] ; then Ver=$i;fi;done
if [ $Ver -gt 0 ]
then 
    echo "Host: $nfsHost supports NFS version $Ver"; 
    mount -o vers=$Ver...........
fi