UDEVD(8) udevd UDEVD(8)

# [NAME](#NAME)

udevd - Device event managing daemon

# [SYNOPSIS](#SYNOPSIS)

udevd

**/sbin/udevd** \[**--daemon**] \[**--debug**] \[**--children-max=**] \[**--exec-delay=**] \[**--event-timeout=**] \[**--resolve-names=early|late|never**] \[**--version**] \[**--help**]

# [DESCRIPTION](#DESCRIPTION)

**udevd** listens to kernel uevents. For every event, udevd executes matching instructions specified in udev rules. See [**udev**(7)](/man/os/eudev/udev.7).

The behavior of the daemon can be configured using [**udev.conf**(5)](/man/os/eudev/udev.conf.5), its command-line options, environment variables, and on the kernel command-line, or changed dynamically with **udevadm control**.

# [OPTIONS](#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 30 seconds.

**-N**, **--resolve-names=**

Specify when 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.

**-h**, **--help**

# [KERNEL COMMAND LINE](#KERNEL_COMMAND_LINE)

Parameters starting with "rd." will be read when **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](#SEE_ALSO)

[**udev.conf**(5)](/man/os/eudev/udev.conf.5), [**udev**(7)](/man/os/eudev/udev.7), [**udevadm**(8)](/man/os/eudev/udevadm.8)

eudev

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Document: udevd(8) from eudev 3.2.14-r51 (Chainguard OS)