nfs mount with nfs 3
Solution 1:
You have misspelled nfsvers=3 and no_root_squash.
Solution 2:
nfsvers is an option.
<server>:</remote/export> </local/directory> <nfs-type> <options> 0 0
It seems that you missed the nsf-type. Changing nfsmount.conf may solve the problem in a system that will never work with nfs4. I have faced the same problem and it was solved like this in your fstab
172.16.11.87:/volume1/web /home/nas nfs nfsvers=3 0 0