NFS4 Client Configuration ?

I'm using Ubuntu 17.10 on a number of computers that use NFS4 to connect to NFS Shares on a File Server. Two of the NFS Clients are Laptop computers, and these are the ones that are causing me problems .

The following is an example of a typical fstab entry that I'm using on the laptops:

192.168.2.2:/volume1/System76 /home/royg/accounts _netdev,auto,rsize=8192,wsize=8192,soft,timeo=14,intr

(Note: there is actually a space between "/home/royg/accounts" and "_netdev" --- the space is not obvious in this font).

I added the modifiers "_netdev,auto" in the expectation that "_netdev" would cause the nfs entry in fstab to be skipped at boot, if the network or the NFS server wasn't available, and added the "auto" in the expectation that this would force the NFS share to be mounted later when the server was available.

Unfortunately, with this fstab line, the laptop is still very slow to boot, if the network is unavailable, or if the NFS Server is not available - and being notebook computers, which are often used away from the office, this situation occurs often.

Can anyone advise what NFS4 Client configuration is required on a laptop computer to:

1) Enable the laptop to boot quickly if the NFS Server is not available, or the network is not available, and
2) Enable automounting of the nfs share on the laptop computer once the Network and NFS Server are available.

Many thanks,

RoyG