fstab-sync(8) -- Linux man page
NAME
fstab-sync - Update the
/etc/fstab
file in response to HAL events
SYNOPSIS
fstab-sync
[-cv?] [-a|--add UDI] [-r|--remove UDI] [-c|--clean]
[-v|--verbose] [-?|--help] [--usage]
DESCRIPTION
This program serves one major purpose: Update the file systems table file
/etc/fstab
and create/remove mount points in
/media
in response to HAL events. This program is usually never run directly
from a shell; instead it is invoked as a callout from the
/etc/hal/device.d
directory by the HAL daemon.
Additionally, this program offers an option of removing any trace of
its previous actions from the file systems table file. Specifically
this happens when invoked by the HAL daemon for the root computer
device object which only happens when the HAL daemon is starting
up. Thus, when starting the HAL daemon, the
/etc/fstab
file will be completely sanitized, e.g. all entries previously added
by the
fstab-sync
program will be removed. When probing for hardware during the
startup of the HAL daemon, the
fstab-sync
program will be invoked several times to add new entries to the
/etc/fstab
file.
All entries added to
/etc/fstab
by
fstab-sync
can be identified by the use of the option
managed
in the options field. This option is a no-op; it is only used to uniquely
identify entries added by the
fstab-sync
program.
When the
/etc/fstab
file is written by
fstab-sync,
a comment with a link to this manual page is added to the file.
CONTROLLING WHAT ENTRIES TO ADD
The
fstab-sync
program relies on properties on the relevant HAL device objects in
order to determine if and how an entry to the
/etc/fstab
file should be added. Specifically, entries are added for hal device
objects of respectively capability
storage
and
volume
only if appropriate
storage.policy
and
volume.policy
properties are set. Also, the
storage.policy.default
properties on the root computer device object are taken into account.
See the HAL specification on
http://freedesktop.org/Software/hal
for more information.
By default, the
/usr/share/hal/fdi/90defaultpolicy/storage-policy.fdi
file specifies the policy - this file should never be edited by the
system administrator as it might get updated by the OS vendor for security
updates. Instead, system- or site-specific rules can be put in
the
/usr/share/hal/fdi/95userpolicy
directory.
Device information files are processed for every hal device object in the
/usr/share/hal/fdi/
directory in alphabetical order including directories. Hence, files in the
90defaultpolicy
directory are processed before files
95userpolicy
directory,
95userpolicy/a.fdi
is processed before
95userpolicy/b.fdi
and so on. In addition, directives in specific files are processed in a
top-down fashion.
A number of sample policy files for various uses should
be available in the
/usr/share/doc/hal-0.4.2/conf
directory. For example, the policy file
storage-non-fixed.fdi
ensures that only fixed optical and floppy drives gets tagged as
mountable which ensures that e.g. hard disk partitions on a fixed disk
won't get added to the
/etc/fstab
file. Similarly the
storage-skip-all.fdi
file will ensure no entries are ever added.
DISABLING FSTAB-SYNC
Automatic updates of the
/etc/fstab
file by the
fstab-sync
program from the HAL daemon can be disabled by changing the
50-fstab-sync.hal
symlink in
/etc/hal/device.d
directory to point to
/bin/false
OPTIONS
The following options are supported:
- --add=UDI
-
Add an entry to the
/etc/fstab
file by giving a HAL Unique Device Identifier
- --remove=UDI
-
Remove an entry from fstab by giving a HAL Unique Device Identifier
- --clean
-
Clean all entries generated by
fstab-sync
from the
/etc/fstab
file
- --verbose
-
Report detailed information about operation progress
- --usage
-
Display brief usage message
- --help
-
Show options
LOCKING
The
fstab-sync
program uses
flock(2)
for locking the
/etc/fstab
file when adding or removing entries. This happens when the HAL daemon
starts up, when there's a media change event or when a storage device
is hotplugged.
SEE ALSO
fstab(5),
http://freedesktop.org/Software/hal
BUGS
One known bug is that the HAL daemon has to be running when cleaning
the
/etc/fstab
file. Please send bug reports to the appropriate distribution bug
tracker or the HAL mailing list - see
http://freedesktop.org/Software/HalTraces for more information.
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