systemd-udevd.service

systemd
Developer Kay Sievers kay@vrfy.org
systemd-udevd.service 8
systemd-udevd.service systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd Device event managing daemon

`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 daemon can be configured using udev.conf 5, its command line options, environment variables, and on the kernel command line, or changed dynamically with `udevadm control`.

## Options

`-d`
`--daemon`

  Detach and run in the background.

`-D`
`--debug`

  Print debug messages to standard error.

`-c=`
`--children-max=`

  Limit the number of events executed in parallel.

`-e=`
`--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.

`-t=`
`--event-timeout=`

  Set the number of seconds to wait for events to finish. After this time, the event will be terminated. The default is 180 seconds.

`-N=`
`--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.

## 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 log level.

`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