System information

Important
The nfs-utils package is now a part of both the 'NFS file server' and the 'Network File System
Client' groups. As such, it is no longer installed by default with the Base group. Ensure that
nfs-utils is installed on the system first before attempting to automount an NFS share.
autofs is also part of the 'Network File System Client' group.
auto fs uses /etc/auto . master (master map) as its default primary configuration file. This can be
changed to use another supported network source and name using the auto fs configuration (in
/etc/sysco nfi g /auto fs) in conjunction with the Name Service Switch (NSS) mechanism. An
instance of the auto fs version 4 daemon was run for each mount point configured in the master
map and so it could be run manually from the command line for any given mount point. This is not
possible with auto fs version 5, because it uses a single daemon to manage all configured mount
points; as such, all automounts must be configured in the master map. This is in line with the usual
requirements of other industry standard automounters. Mount point, hostname, exported directory,
and options can all be specified in a set of files (or other supported network sources) rather than
configuring them manually for each host.
9.4 .1. Improvement s in aut ofs Version 5 over Version 4
auto fs version 5 features the following enhancements over version 4:
Direct map su p p o rt
Direct maps in auto fs provide a mechanism to automatically mount file systems at
arbitrary points in the file system hierarchy. A direct map is denoted by a mount point of /-
in the master map. Entries in a direct map contain an absolute path name as a key (instead
of the relative path names used in indirect maps).
Laz y mo u nt an d u n mo u n t su p p o rt
Multi-mount map entries describe a hierarchy of mount points under a single key. A good
example of this is the -ho sts map, commonly used for automounting all exports from a
host under /net/host as a multi-mount map entry. When using the -ho sts map, an l s of
/net/host will mount autofs trigger mounts for each export from host. These will then
mount and expire them as they are accessed. This can greatly reduce the number of active
mounts needed when accessing a server with a large number of exports.
En h an ced LDAP su p p ort
The auto fs configuration file (/etc/sysco nfi g /auto fs) provides a mechanism to
specify the auto fs schema that a site implements, thus precluding the need to determine
this via trial and error in the application itself. In addition, authenticated binds to the LDAP
server are now supported, using most mechanisms supported by the common LDAP server
implementations. A new configuration file has been added for this support:
/etc/auto fs_l d ap_auth. co nf. The default configuration file is self-documenting, and
uses an XML format.
Pro p er u se o f t he N ame Service Swit ch ( nsswi tch) conf ig u rat io n .
The Name Service Switch configuration file exists to provide a means of determining from
where specific configuration data comes. The reason for this configuration is to allow
administrators the flexibility of using the back-end database of choice, while maintaining a
uniform software interface to access the data. While the version 4 automounter is becoming
⁠Chapt er 9 . Net work File Syst em (NFS)
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