SYSTEMD.KILL(5) systemd.kill SYSTEMD.KILL(5)
NAME
systemd.kill - Process killing procedure configuration
SYNOPSIS
service.service, socket.socket, mount.mount, swap.swap, scope.scope
DESCRIPTION
Unit configuration files for services, sockets, mount points, swap
devices and scopes share a subset of configuration options which define
the killing procedure of processes belonging to the unit.
This man page lists the configuration options shared by these five unit
types. See systemd.unit(5) for the common options shared by all unit
configuration files, and systemd.service(5), systemd.socket(5),
systemd.swap(5), systemd.mount(5) and systemd.scope(5) for more
information on the configuration file options specific to each unit
type.
The kill procedure configuration options are configured in the
[Service], [Socket], [Mount] or [Swap] section, depending on the unit
type.
OPTIONS
KillMode=
Specifies how processes of this unit shall be killed. One of
control-group, process, mixed, none.
If set to control-group, all remaining processes in the control
group of this unit will be killed on unit stop (for services: after
the stop command is executed, as configured with ExecStop=). If set
to process, only the main process itself is killed. If set to
mixed, the SIGTERM signal (see below) is sent to the main process
while the subsequent SIGKILL signal (see below) is sent to all
remaining processes of the unit's control group. If set to none, no
process is killed. In this case, only the stop command will be
executed on unit stop, but no process will be killed otherwise.
Processes remaining alive after stop are left in their control
group and the control group continues to exist after stop unless it
is empty.
Processes will first be terminated via SIGTERM (unless the signal
to send is changed via KillSignal= or RestartKillSignal=).
Optionally, this is immediately followed by a SIGHUP (if enabled
with SendSIGHUP=). If processes still remain after the main process
of a unit has exited or the delay configured via the
TimeoutStopSec= has passed, the termination request is repeated
with the SIGKILL signal or the signal specified via
FinalKillSignal= (unless this is disabled via the SendSIGKILL=
option). See kill(2) for more information.
Defaults to control-group.
KillSignal=
Specifies which signal to use when stopping a service. This
controls the signal that is sent as first step of shutting down a
unit (see above), and is usually followed by SIGKILL (see above and
below). For a list of valid signals, see signal(7). Defaults to
SIGTERM.
Note that, right after sending the signal specified in this
setting, systemd will always send SIGCONT, to ensure that even
suspended tasks can be terminated cleanly.
RestartKillSignal=
Specifies which signal to use when restarting a service. The same
as KillSignal= described above, with the exception that this
setting is used in a restart job. Not set by default, and the value
of KillSignal= is used.
SendSIGHUP=
Specifies whether to send SIGHUP to remaining processes immediately
after sending the signal configured with KillSignal=. This is
useful to indicate to shells and shell-like programs that their
connection has been severed. Takes a boolean value. Defaults to
"no".
SendSIGKILL=
Specifies whether to send SIGKILL (or the signal specified by
FinalKillSignal=) to remaining processes after a timeout, if the
normal shutdown procedure left processes of the service around.
When disabled, a KillMode= of control-group or mixed service will
not restart if processes from prior services exist within the
control group. Takes a boolean value. Defaults to "yes".
FinalKillSignal=
Specifies which signal to send to remaining processes after a
timeout if SendSIGKILL= is enabled. The signal configured here
should be one that is not typically caught and processed by
services (SIGTERM is not suitable). Developers can find it useful
to use this to generate a coredump to troubleshoot why a service
did not terminate upon receiving the initial SIGTERM signal. This
can be achieved by configuring LimitCORE= and setting
FinalKillSignal= to either SIGQUIT or SIGABRT Defaults to SIGKILL.
WatchdogSignal=
Specifies which signal to use to terminate the service when the
watchdog timeout expires (enabled through WatchdogSec=). Defaults
to SIGABRT.
SEE ALSO
systemd(1), systemctl(1), journalctl(1), systemd.unit(5),
systemd.service(5), systemd.socket(5), systemd.swap(5),
systemd.mount(5), systemd.exec(5), systemd.directives(7), kill(2),
signal(7)
systemd 245 SYSTEMD.KILL(5)