NFS stands for Network File System, and is a way to share files between machines as if they were on your local hard drive. Linux can be both an NFS server and an NFS client, which means that it can export filesystems to other systems, and mount filesystems exported from other machines.

Use the mount command to mount a NFS filesystem from another machine:

mount porky:/mnt/export /mnt/local

In this command, porky is the hostname of the NFS fileserver, /mnt/export is the filesystem that porky is exporting, and /mnt/local is a directory on my local machine where we want to mount the filesystem. After the mount command runs (and if we have the proper permissions from porky) we can enter ls /mnt/local and get a listing of the files in /mnt/export on porky.

The file that controls what filesystems you wish to export is /etc/exports. Its format is:

directory       hostname(options)

the (options) are optional. For example:

/mnt/export     speedy.redhat.com

would allow speedy.redhat.com to mount /mnt/export, but:

/mnt/export     speedy.redhat.com(ro)

would just allow speedy to mount /mnt/export read-only.

Each time you change /etc/exports, you need to tell the NFS daemons to examine it for new information. One simple way to accomplish this is to just stop and start the daemons:

/etc/rc.d/init.d/nfs stop
/etc/rc.d/init.d/nfs start

The following will also work:

killall -HUP rpc.nfsd rpc.mountd