Importing File Systems Manually

File systems can also be imported manually from an NFS server. The prerequisite for this is a running RPC port mapper, which can be started by entering rcportmap start as root. Once this prerequisite is met, remote exported file systems can be mounted in the file system just like local hard disks using the mount command in the following manner:

mount host:remote-path local-path

If user directories from the machine sun, for example, should be imported, use the following command:

mount sun:/home /home

Importing NFSv4 File Systems

The idmapd service must be up and running on the client to do an NFSv4 import. Start the idmapd service from the command prompt with rcidmapd start. Use rcidmapd status to check the status of idmapd.

The idmapd services stores its parameters in the /etc/idmapd.conf file. Leave the value of the Domain parameter as localdomain. Ensure that the value specified is the same for both the NFS client and NFS server.

Make NFSv4 imports by giving a command from the shell prompt. To import NFSv4 remote file systems, use the following command:

mount -t nfs4 host:/ local-path

Replace host with the NFS server that hosts one or more NFSv4 exports and local-path with the directory location in the client machine where this should be mounted. For example, to import /home exported with NFSv4 on sun to /local/home, use the following command:

mount -t nfs4 sun:/ /local/home

The remote file system path that follows the server name and a colon is a slash “/”. This is unlike the way it is specified for v3 imports, where the exact path of the remote file system is given. This is a concept called pseudo file system, which is explained in Section 37.4.1, “Exporting for NFSv4 Clients”.

Using the Automount Service

As well as the regular local device mounts, the autofs daemon can be used to mount remote file systems automatically too. To do this, add the following entry in the your /etc/auto.master file:

/nfsmounts /etc/auto.nfs

Now the /nfsmounts directory acts as a root for all the NFS mounts on the client if the auto.nfs file is completed appropriately. The name auto.nfs is chosen for sake of convenience—you can choose any name. In the selected file (create it if it does not exist), add entries for all the NFS mounts as in the following example:

localdata -fstype=nfs server1:/data
nfs4mount -fstype=nfs4 server2:/

Activate the settings with rcautofs start. For this example, /nfsmounts/localdata, the /data directory of server1, is then mounted with NFS and /nfsmounts/nfs4mount from server2 is mounted with NFSv4.

If the /etc/auto.master file is edited while the service autofs is running, the automounter must be restarted for the changes to take effect. Do this with rcautofs restart.

Manually Editing /etc/fstab

A typical NFS mount entry in /etc/fstab looks like this:

host:/data /local/path nfs rw,noauto 0 0

NFSv4 mounts may also be added to the /etc/fstab file manually. For these mounts, use nfs4 instead of nfs in the third column and make sure that the remote file system is given as / after the host: in the first column. The advantage of saving this information in /etc/fstab is that commands for mounting can be shortened to just mentioning the local mount point alone, for example:

mount /local/path