This section describes how AutoFS works.
AutoFS mounts directories automatically when users or processes request
access to them, and it unmounts directories automatically if they remain
idle for a period of time (10 minutes, by default).
When deciding if AutoFS is right for your environment, see “Deciding
Between Standard-Mounted Directories and Automounted Directories”.
AutoFS consists of the following components:
The automount command which reads AutoFS maps into memory
The automountd daemon, which automounts filesystems when they are
accessed by users or applications
The automount command reads the AutoFS master map to create
the initial set of AutoFS mount points in the kernel mount table, /etc/mnttab. The automounted filesystems are not automatically mounted
at startup. They are points under which filesystems are mounted
later, when users or applications request access to them.
When AutoFS receives a request to mount a filesystem, it calls
the automountd daemon, which mounts the requested filesystem.
Once the filesystem is mounted, further access does not require
any action from the automountd daemon.
The automountd daemon is independent from the automount command. As a result, you can add, delete, or
change map information without stopping and restarting the automountd daemon.
Once AutoFS starts and the mount points are set up, you can
modify the set of mount points by modifying maps and running the automount command, to read them and modify the mount table
accordingly. You need not stop and restart AutoFS.
If an automounted filesystem remains idle for 10 minutes (the
default), AutoFS unmounts it.
For more information on AutoFS, see automount(1M) and
automountd(1M).
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 | CAUTION: Filesystems under the management of AutoFS must always
be maintained using the AutoFS utilities automountd and automount. Manually mounting and unmounting
AutoFS-managed filesystems can lead to disruptive or unpredictable
results, including but not limited to: commands hanging or not returning
expected results, and applications failing because of their dependencies
on these mounted filesystems. |
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Supported
Filesystems |
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AutoFS can mount the following filesystems:
On-Demand
Mounting |
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In HP-UX 11i v3, the filesystems being accessed are mounted automatically
and other filesystems that are hierarchically related to these filesystems
are mounted only when needed.
In the following example, the AutoFS master and direct maps
are on the NFS client, sage:
# /etc/auto_master file
# local mount point map name mount options
/- /etc/auto_direct |
# /etc/auto_direct file
# local mount point mount options remote server:directory
/auto/project/specs -nosuid thyme:/export/project/specs
/auto/project/specs/reqmnts -nosuid / sage:/export/projects/specs/reqmnts
/auto/project/specs/reqmnts -nosuid |
A user on the NFS client, sage,
enters the following command:
Only the /auto/project/specs subdirectory is mounted. The /auto/project/specs/designs subdirectory is mounted only when accessed using the
following command:
cd /auto/project/specs/designs |
shows the
automounted file structure after the user runs the command.
Browsability
for Indirect Maps |
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AutoFS now allows you to view the potential mount points for
indirect maps, without mounting each filesystem.
In the following example, the AutoFS master and indirect maps
are on the NFS client, sage:
# /etc/auto_master file
# local mount point map name mount options
/nfs/desktop /etc/auto_indirect |
# /etc/auto_indirect file
# local mount point mount options remote server:directory
/test -nosuid thyme:/export/project/test
/apps -nosuid basil:/export/apps |
Enter the following commands:
The ls command displays the following:
The test and apps subdirectories are the potential mount points. However,
they are not currently mounted, but if you enter the following commands,
both test and apps subdirectories are mounted:
cd /nfs/desktop/test
cd /nfs/desktop/apps |
Browsing is enabled by default for all indirect AutoFS maps.
To disable browsing for a specific indirect map, specify the -nobrowse option for that map. Optionally,
you can disable browsing for all indirect maps by launching automountd with the -n option.
NFS
Loopback Mount |
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By default, AutoFS uses the Loopback Filesystem (LOFS) mount
for locally mounted filesystems. AutoFS provides an option to allow
the loopback NFS mounts for the local mount. The automountd command with the -L option is used to enable the loopback
NFS mounts for locally mounted filesystems. This option is useful
when AutoFS is running on a node that is part of a High Availability
NFS environment.
Map
Locations (Backends) |
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AutoFS maps can be located in the following:
Files: A local
file that stores the AutoFS map information. An example of a map
that can be kept on the local system is the master map. The
AUTO_MASTER variable in /etc/rc.config.d/nfsconf is set to the name of the master map. The default
master map name is /etc/auto_master.
Network Information Service
(NIS): A service that allows you to administer the configuration
of many hosts from a central location. Common configuration information,
which would have to be maintained separately on each host in a network
without NIS, can be stored and maintained in a central location
and propagated to all of the nodes in the network.
For
more information on NIS, see NIS Administrator’s Guide (5991-7656).
LDAP: A directory service
that stores information, which is retrieved by clients throughout
the network. The LDAP-UX Integration product centralizes user, group,
and network information management in an LDAP directory, to simplify
HP-UX system administration.
For more information
on the LDAP-UX Integration product, see the LDAP-UX Client
Services B.04.00 Administrator’s Guide (J4269-90064).
To use NIS or LDAP maps, you need to perform the following:
Configure the
/etc/nsswitch.conf file
This file enables you to specify
one or more data stores to look up information (in this case, AutoFS
maps). You can also specify the order in which these data sources
are looked up. LDAP and NIS can be specified to lookup AutoFS maps.
For
more information on configuring the /etc/nsswitch.conf file, see nsswitch.conf (4).
Configure AutoFS maps in
LDAP or NIS
You need to set up your AutoFS maps
on the specified data store.
For information on setting
up AutoFS maps on NIS, see NIS Administrator’s
Guide (5991-7656).
For information
on setting up AutoFS maps for LDAP, see “Enabling
AutoFS for LDAP Support”.
Enabling
AutoFS for LDAP Support |
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To enable AutoFS for LDAP support, follow these steps:
Migrate your AutoFS maps to LDIF (LDAP
Directory Interchange Format) files, using the migration scripts,
if the AutoFS maps are not already migrated.
For information on the specific migration scripts, see LDAP-UX Client
Services B.04.10 Administrator’s Guide (J4269-90067).
Import the LDIF files in to the LDAP directory server
using the ldapmodify tool.
For information on the migration scripts, see the LDAP-UX
Client Services B.04.10 Administrator’s Guide (J4269-90067).
Check whether the nisObject automount schema exists in the /var/opt/netscape/servers/slapd-<server-instance>/config/schema/10rfc2307.ldif file in the LDAP directory, by searching for entries
that contain the following fields:
• NAME ‘nisMapName’• NAME ‘nisMapEntry’• NAME ‘nisObject’• NAME ‘nisMap’ |
If the entries do not exist, set up the attribute mappings
on the LDAP-UX client. For more information, see the LDAP-UX
Client Services B.04.10 Administrator’s Guide (J4269-90067).
Configure the Name Service Switch (NSS), to enable
AutoFS for LDAP support.
Backup the current /etc/nsswitch.conf file. Then modify the working file, to add an entry for
LDAP support to the automount service as follows:
Enter the following command to run the AutoFS shutdown
script:
Enter the following command to run the AutoFS startup
script:
/sbin/init.d/autofs start |
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