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openSUSE 11.1 Reference Guide
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27.5 Exporting File Systems Manually

The configuration files for the NFS export service are /etc/exports and /etc/sysconfig/nfs. In addition to these files, /etc/idmapd.conf is needed for the NFSv4 server configuration. To start or restart the services, run the command rcnfsserver restart. This also starts the rpc.idmapd if NFSv4 is configured in /etc/sysconfig/nfs. The NFS server depends on a running RPC portmapper. Therefore, also start or restart the portmapper service with rcrpcbind restart.

27.5.1 Exporting File Systems with NFSv4

NFSv4 is the latest version of NFS protocol available on openSUSE. Configuring the directories for export with NFSv4 differs slightly from the previous NFS versions.

The /etc/exports File

This file contains a list of entries. Each entry indicates a directory that is shared and how it is shared. A typical entry in /etc/exports consists of:

/shared/directory host(option_list)

For example:


For those directories— called pseudo root file system— fsid=0 is specified in the option list. Here, the IP address is used. You can use the name of the host, a wild card indicating a set of hosts (*, *, etc.), or netgroups.

For a fixed set of clients, there are only two types of directories that can be NFSv4 exported:

  • A single directory that is chosen as the pseudo root file system. In this example, /export is the pseudo root directory because fsid=0 is specified in the option list for this entry.

  • Directories that are chosen to be bound to some existing subdirectory of the pseudo file system. In the example entries above, /data is such a directory that binds to an existing subdirectory (/export/data) of the pseudo file system /export.

The pseudo file system is the top level directory under which all file systems that need to be NFSv4 exported take their places. For a client or set of clients, there can only be one directory on the server configured as the pseudo root for export. For this client or client set, multiple other directories can be exported by binding them to some existing subdirectory in the pseudo root.


This file contains a few parameters that determine NFSv4 server daemon behavior. Importantly, the parameter NFSv4_SUPPORT must be set to yes. This parameter determines whether the NFS server supports NFSv4 exports and clients.


Every user on a Linux machine has a name and ID. idmapd does the name-to-ID mapping for NFSv4 requests to the server and replies to the client. This must be running on both server and client for NFSv4, because NFSv4 uses only names for its communication.

Make sure that there is a uniform way in which usernames and IDs (uid) are assigned to users across machines that might probably be sharing file systems using NFS. This can be achieved by using NIS, LDAP, or any uniform domain authentication mechanism in your domain.

For proper function, the parameter Domain must be set the same for both, client and server in this file. If you are not sure, leave the domain as localdomain in the server and client files. A sample configuration file looks like the following:


Verbosity = 0 
Pipefs-Directory = /var/lib/nfs/rpc_pipefs
Domain = localdomain


Nobody-User = nobody
Nobody-Group = nobody

Do not change these parameters unless you know exactly what you are doing. For further reference, read the man page of idmapd and idmapd.conf; man idmapd, man idmapd.conf.

Starting and Stopping Services

After changing /etc/exports or /etc/sysconfig/nfs, start or restart the nfs server service with rcnfsserver restart. After changing /etc/idmapd.conf, reload the configuration file with the command killall -HUP rpc.idmapd.

If this service should start at boot time, run the command chkconfig nfsserver on.

27.5.2 Exporting File Systems with NFSv2 and NFSv3

This is specific to NFSv3 and NFSv2 exports. Refer to Exporting for NFSv4 Clients for exporting with NFSv4.

Exporting file systems with NFS involves two configuration files: /etc/exports and /etc/sysconfig/nfs. A typical /etc/exports file entry is in the format:

/shared/directory host(list_of_options)

For example:


Here, the directory /export is shared with the host with the option list rw,sync. This IP address can be replaced with a client name or set of clients using a wild card (such as * or even netgroups.

For a detailed explanation of all options and their meanings, refer to the man page of exports (man exports).

After changing /etc/exports or /etc/sysconfig/nfs, start or restart the NFS server using the command rcnfsserver restart.

openSUSE 11.1 Reference Guide
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  Published under the terms fo the GNU General Public License Design by Interspire