NAME | SYNOPSIS | DESCRIPTION | PRESET FILE FORMAT | EXAMPLE | SEE ALSO | NOTES | COLOPHON

SYSTEMD.PRESET(5)              systemd.preset              SYSTEMD.PRESET(5)

NAME         top

       systemd.preset - Service enablement presets

SYNOPSIS         top

       /etc/systemd/system-preset/*.preset

       /run/systemd/system-preset/*.preset

       /usr/lib/systemd/system-preset/*.preset

       /etc/systemd/user-preset/*.preset

       /run/systemd/user-preset/*.preset

       /usr/lib/systemd/user-preset/*.preset

DESCRIPTION         top

       Preset files may be used to encode policy which units shall be
       enabled by default and which ones shall be disabled. They are read by
       systemctl preset (for more information see systemctl(1)) which uses
       this information to enable or disable a unit according to preset
       policy.  systemctl preset is used by the post install scriptlets of
       RPM packages (or other OS package formats), to enable/disable
       specific units by default on package installation, enforcing
       distribution, spin or administrator preset policy. This allows
       choosing a certain set of units to be enabled/disabled even before
       installing the actual package.

       For more information on the preset logic please have a look at the
       Presets[1] document.

       It is not recommended to ship preset files within the respective
       software packages implementing the units, but rather centralize them
       in a distribution or spin default policy, which can be amended by
       administrator policy.

       If no preset files exist, systemctl preset will enable all units that
       are installed by default. If this is not desired and all units shall
       rather be disabled, it is necessary to ship a preset file with a
       single, catchall "disable *" line. (See example 1, below.)

PRESET FILE FORMAT         top

       The preset files contain a list of directives consisting of either
       the word "enable" or "disable" followed by a space and a unit name
       (possibly with shell style wildcards), separated by newlines. Empty
       lines and lines whose first non-whitespace character is # or ; are
       ignored.

       Presets must refer to the "real" unit file, and not to any aliases.
       See systemd.unit(5) for a description of unit aliasing.

       Two different directives are understood: "enable" may be used to
       enable units by default, "disable" to disable units by default.

       If multiple lines apply to a unit name, the first matching one takes
       precedence over all others.

       Each preset file shall be named in the style of
       <priority>-<policy-name>.preset. Files in /etc/ override files with
       the same name in /usr/lib/ and /run/. Files in /run/ override files
       with the same name in /usr/lib/. Packages should install their preset
       files in /usr/lib/. Files in /etc/ are reserved for the local
       administrator, who may use this logic to override the preset files
       installed by vendor packages. All preset files are sorted by their
       filename in lexicographic order, regardless of which of the
       directories they reside in. If multiple files specify the same unit
       name, the entry in the file with the lexicographically earliest name
       will be applied. It is recommended to prefix all filenames with a
       two-digit number and a dash, to simplify the ordering of the files.

       If the administrator wants to disable a preset file supplied by the
       vendor, the recommended way is to place a symlink to /dev/null in
       /etc/systemd/system-preset/ bearing the same filename.

EXAMPLE         top

       Example 1. Default off example
       /usr/lib/systemd/system-preset/99-default.preset:

           disable *

       This disables all units. Due to the filename prefix "99-", it will be
       read last and hence can easily be overridden by spin or administrator
       preset policy or suchlike.

       Example 2. A GNOME spin example
       /usr/lib/systemd/system-preset/50-gnome.preset:

           enable gdm.service
           enable colord.service
           enable accounts-daemon.service
           enable avahi-daemon.*

       This enables the three mentioned units, plus all avahi-daemon
       regardless of which unit type. A file like this could be useful for
       inclusion in a GNOME spin of a distribution. It will ensure that the
       units necessary for GNOME are properly enabled as they are installed.
       It leaves all other units untouched, and subject to other (later)
       preset files, for example like the one from the first example above.

       Example 3. Administrator policy
       /etc/systemd/system-preset/00-lennart.preset:

           enable httpd.service
           enable sshd.service
           enable postfix.service
           disable *

       This enables three specific services and disables all others. This is
       useful for administrators to specifically select the units to enable,
       and disable all others. Due to the filename prefix "00-" it will be
       read early and hence overrides all other preset policy files.

SEE ALSO         top

       systemd(1), systemctl(1), systemd-delta(1)

NOTES         top

        1. Presets
           http://freedesktop.org/wiki/Software/systemd/Preset

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have a bug
       report for this manual page, see 
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.  This
       page was obtained from the project's upstream Git repository 
       ⟨https://github.com/systemd/systemd.git⟩ on 2016-09-01.  If you dis‐
       cover any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

systemd 231                                                SYSTEMD.PRESET(5)