9.3. NFS Client Configuration
The
mount command mounts NFS shares on the client side. Its format is as follows:
# mount -t nfs -o options server:/remote/export /local/directory
This command uses the following variables:
- options
- A comma-delimited list of mount options; refer to Section 9.5, “Common NFS Mount Options” for details on valid NFS mount options.
- server
- The hostname, IP address, or fully qualified domain name of the server exporting the file system you wish to mount
- /remote/export
- The file system or directory being exported from the server, that is, the directory you wish to mount
- /local/directory
- The client location where /remote/export is mounted
The NFS protocol version used in Red Hat Enterprise Linux 6 is identified by the
mount options nfsvers or vers. By default, mount will use NFSv4 with mount -t nfs. If the server does not support NFSv4, the client will automatically step down to a version supported by the server. If the nfsvers/vers option is used to pass a particular version not supported by the server, the mount will fail. The file system type nfs4 is also available for legacy reasons; this is equivalent to running mount -t nfs -o nfsvers=4 host:/remote/export /local/directory.
Refer to
man mount for more details.
If an NFS share was mounted manually, the share will not be automatically mounted upon reboot. Red Hat Enterprise Linux offers two methods for mounting remote file systems automatically at boot time: the
/etc/fstab file and the autofs service. Refer to Section 9.3.1, “Mounting NFS File Systems using /etc/fstab” and Section 9.4, “autofs” for more information.
9.3.1. Mounting NFS File Systems using /etc/fstab
An alternate way to mount an NFS share from another machine is to add a line to the
/etc/fstab file. The line must state the hostname of the NFS server, the directory on the server being exported, and the directory on the local machine where the NFS share is to be mounted. You must be root to modify the /etc/fstab file.
Example 9.1. Syntax example
The general syntax for the line in
/etc/fstab is as follows:
server:/usr/local/pub /pub nfs defaults 0 0
The mount point
/pub must exist on the client machine before this command can be executed. After adding this line to /etc/fstab on the client system, use the command mount /pub, and the mount point /pub is mounted from the server.
The
/etc/fstab file is referenced by the netfs service at boot time, so lines referencing NFS shares have the same effect as manually typing the mount command during the boot process.
A valid
/etc/fstab entry to mount an NFS export should contain the following information:
server:/remote/export /local/directory nfs options 0 0
The variables server, /remote/export, /local/directory, and options are the same ones used when manually mounting an NFS share. Refer to Section 9.3, “NFS Client Configuration” for a definition of each variable.
Note
The mount point /local/directory must exist on the client before
/etc/fstab is read. Otherwise, the mount will fail.
For more information about
/etc/fstab, refer to man fstab.
