nfs fails to mount on bootup

Check if rpcbind is running.

service rpcbind status|start|stop|restart

Or you can also clean the NFS cache.

service rpcbind stop
service nfslock stop
rm -rf /var/lib/nfs/statd/sm/*
rm -rf /var/lib/nfs/statd/sm.bak/*
service rpcbind start
service nfslock start