oomd.conf(5) — Linux manual page


OOMD.CONF(5)                    oomd.conf                   OOMD.CONF(5)

NAME         top

       oomd.conf, oomd.conf.d - Global systemd-oomd configuration files

SYNOPSIS         top


DESCRIPTION         top

       These files configure the various parameters of the systemd(1)
       userspace out-of-memory (OOM) killer, systemd-oomd.service(8).
       See systemd.syntax(7) for a general description of the syntax.


       The default configuration is set during compilation, so
       configuration is only needed when it is necessary to deviate from
       those defaults. The main configuration file is either in
       /usr/lib/systemd/ or /etc/systemd/ and contains commented out
       entries showing the defaults as a guide to the administrator.
       Local overrides can be created by creating drop-ins, as described
       below. The main configuration file can also be edited for this
       purpose (or a copy in /etc/ if it's shipped in /usr/) however
       using drop-ins for local configuration is recommended over
       modifications to the main configuration file.

       In addition to the "main" configuration file, drop-in
       configuration snippets are read from /usr/lib/systemd/*.conf.d/,
       /usr/local/lib/systemd/*.conf.d/, and /etc/systemd/*.conf.d/.
       Those drop-ins have higher precedence and override the main
       configuration file. Files in the *.conf.d/ configuration
       subdirectories are sorted by their filename in lexicographic
       order, regardless of in which of the subdirectories they reside.
       When multiple files specify the same option, for options which
       accept just a single value, the entry in the file sorted last
       takes precedence, and for options which accept a list of values,
       entries are collected as they occur in the sorted files.

       When packages need to customize the configuration, they can
       install drop-ins under /usr/. Files in /etc/ are reserved for the
       local administrator, who may use this logic to override the
       configuration files installed by vendor packages. Drop-ins have
       to be used to override package drop-ins, since the main
       configuration file has lower precedence. It is recommended to
       prefix all filenames in those subdirectories with a two-digit
       number and a dash, to simplify the ordering of the files. This
       also defined a concept of drop-in priority to allow distributions
       to ship drop-ins within a specific range lower than the range
       used by users. This should lower the risk of package drop-ins
       overriding accidentally drop-ins defined by users.

       To disable a configuration file supplied by the vendor, the
       recommended way is to place a symlink to /dev/null in the
       configuration directory in /etc/, with the same filename as the
       vendor configuration file.


       The following options are available in the [OOM] section:

           Sets the limit for memory and swap usage on the system before
           systemd-oomd will take action. If the fraction of memory used
           and the fraction of swap used on the system are both more
           than what is defined here, systemd-oomd will act on eligible
           descendant control groups with swap usage greater than 5% of
           total swap, starting from the ones with the highest swap
           usage. Which control groups are monitored and what action
           gets taken depends on what the unit has configured for
           ManagedOOMSwap=. Takes a value specified in percent (when
           suffixed with "%"), permille ("‰") or permyriad ("‱"),
           between 0% and 100%, inclusive. Defaults to 90%.

           Added in version 247.

           Sets the limit for memory pressure on the unit's control
           group before systemd-oomd will take action. A unit can
           override this value with ManagedOOMMemoryPressureLimit=. The
           memory pressure for this property represents the fraction of
           time in a 10 second window in which all tasks in the control
           group were delayed. For each monitored control group, if the
           memory pressure on that control group exceeds the limit set
           for longer than the duration set by
           DefaultMemoryPressureDurationSec=, systemd-oomd will act on
           eligible descendant control groups, starting from the ones
           with the most reclaim activity to the least reclaim activity.
           Which control groups are monitored and what action gets taken
           depends on what the unit has configured for
           ManagedOOMMemoryPressure=. Takes a fraction specified in the
           same way as SwapUsedLimit= above. Defaults to 60%.

           Added in version 247.

           Sets the amount of time a unit's control group needs to have
           exceeded memory pressure limits before systemd-oomd will take
           action. Memory pressure limits are defined by
           DefaultMemoryPressureLimit= and
           ManagedOOMMemoryPressureLimit=. Must be set to 0, or at least
           1 second. Defaults to 30 seconds when unset or 0.

           Added in version 248.

SEE ALSO         top

       systemd(1), systemd.resource-control(5), systemd-oomd.service(8),

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
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
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       (which is not part of the original manual page), send a mail to

systemd 255                                                 OOMD.CONF(5)

Pages that refer to this page: oomctl(1)systemd.resource-control(5)systemd.directives(7)systemd.index(7)systemd-oomd.service(8)