Having multiple clients causes the need to have user's files stored
central and accessed from the clients, i.e. to get /home
to the clients.
People have different opinions about /var/mail. Some
prefer it shared, too. Which allows to divide quota for
mail and normal files. Other prefer changing user's mailboxes
to $HOME/.mail, reducing troubles with locking and mountpoints.
Using a automounter one can let the clients automatically mount
those subdirectories in /home, that are accessed. This
can allow more fine grained permissions, which computer can
access which home-directories. And it makes it possible to
distribute home-directories over several servers or partitions
in a transparent way. (i.e. the user may only see by quota or
df, which server or partition his home-directory is stored on).
As this gives large flexibility, it has so many possible configurations
that none is suitable for so many people to include it here. There
are also no problems replacing a single /home mountpoint over
nfs with this solution, so that one can wait with this until it is
needed.
For more documentation, see http://www.linux-consulting.com/Amd_AutoFS/autofs.html.
Nfs is the oldest and fastest way to get /home anywhere.
Though one should be away speed is bought by reliance on the
security of the local network. Nothing is encrypted and
only authentication is the ip-address.
Currently the kernel-space nfs-server is quite better than the user-space one and should be prefered in order to get locking and higher reliability.
OpenAFS seems to get more widespread in the last time. While it does not rely that heavy on the security of the net, it is also said to be quite difficult to set up. And its complex access control lists and its own users and group handling are of course a two edged sword.
And many many more...