oomd.conf(5) — Linux manual page

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

NAME

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

SYNOPSIS

           /etc/systemd/oomd.conf
           /run/systemd/oomd.conf
           /usr/local/lib/systemd/oomd.conf
           /usr/lib/systemd/oomd.conf
           /etc/systemd/oomd.conf.d/*.conf
           /run/systemd/oomd.conf.d/*.conf
           /usr/local/lib/systemd/oomd.conf.d/*.conf
           /usr/lib/systemd/oomd.conf.d/*.conf

DESCRIPTION

       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.

CONFIGURATION DIRECTORIES AND PRECEDENCE

       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 loaded from one of
       the listed directories in order of priority, only the first file
       found is used: /etc/systemd/, /run/systemd/,
       /usr/local/lib/systemd/ [1], /usr/lib/systemd/. The vendor
       version of the file contains commented out entries showing the
       defaults as a guide to the administrator. Local overrides can
       also 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 under /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. This also defines a
       concept of drop-in priorities to allow OS vendors 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. It is recommended to use
       the range 10-40 for drop-ins in /usr/ and the range 60-90 for
       drop-ins in /etc/ and /run/, to make sure that local and
       transient drop-ins take priority over drop-ins shipped by the OS
       vendor.

       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.

[OOM] SECTION OPTIONS

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

       SwapUsedLimit=
           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.

       DefaultMemoryPressureLimit=
           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.

       DefaultMemoryPressureDurationSec=
           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

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

NOTES

        1. 💣💥🧨💥💥💣 Please note that those configuration files must
           be available at all times. If /usr/local/ is a separate
           partition, it may not be available during early boot, and
           must not be used for configuration.

COLOPHON

       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 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2024-06-13.)  If you discover 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 257~devel                                           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)

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