Index · Directives · Python · libudev · gudev systemd 216

Name

systemd-udevd.service, systemd-udevd-control.socket, systemd-udevd-kernel.socket, systemd-udevd — Device event managing daemon

Synopsis

systemd-udevd.service

systemd-udevd-control.socket

systemd-udevd-kernel.socket

/usr/lib/systemd/systemd-udevd [--daemon] [--debug] [--children-max=] [--exec-delay=] [--event-timeout=] [--resolve-names=early|late|never] [--version] [--help]

Description

systemd-udevd listens to kernel uevents. For every event, systemd-udevd executes matching instructions specified in udev rules. See udev(7).

The behavior of the running daemon can be changed dynamically with udevadm control, or configured using udev.conf(5).

Options

--daemon

Detach and run in the background.

--debug

Print debug messages to standard error.

--children-max=

Limit the number of events executed in parallel.

--exec-delay=

Delay the execution of RUN instructions by the given number of seconds. This option might be useful when debugging system crashes during coldplug caused by loading non-working kernel modules.

--event-timeout=

Set the number of seconds to wait for events to finish. After this time the event will be terminated. The default is 30 seconds.

--resolve-names=

Specify when systemd-udevd should resolve names of users and groups. When set to early (the default), names will be resolved when the rules are parsed. When set to late, names will be resolved for every event. When set to never, names will never be resolved and all devices will be owned by root.

--help

Print a short help text and exit.

--version

Print a short version string and exit.

Environment

$UDEV_LOG=

Set the logging priority.

Kernel command line

Parameters starting with "rd." will be read when systemd-udevd is used in an initrd.

udev.log-priority=, rd.udev.log-priority=

Set the logging priority.

udev.children-max=, rd.udev.children-max=

Limit the number of events executed in parallel.

udev.exec-delay=, rd.udev.exec-delay=

Delay the execution of RUN instructions by the given number of seconds. This option might be useful when debugging system crashes during coldplug caused by loading non-working kernel modules.

udev.event-timeout=, rd.udev.event-timeout=

Wait for events to finish up to the given number of seconds. This option might be useful if events are terminated due to kernel drivers taking too long to initialize.

net.ifnames=

Network interfaces are renamed to give them predictable names when possible. It is enabled by default; specifying 0 disables it.

See Also

udev.conf(5), udev(7), udevadm(8)