I am using NFS to share some important directories (/home, /opt, /local/usr) from a machine to other machines (all OS are Debian 9). Most of the time it works well. However, when the server's network fails, The client machines will have problems of starting up or logging in since these directories cannot be mounted.
I hope to keep these sharings because together with NIS it does make things much easier, and most of the time it does work well. I would like to ask solutions in occasional cases of server network failure. For example, is it possible to set up this way: in case the server is inaccessible online (so the remote NFS directories cannot be mounted in clients), the client can switch automatically to use the local directories to avoid startup or login failure.