1SYSTEMD-UDEVD.SERVICE(8) systemd-udevd.service SYSTEMD-UDEVD.SERVICE(8)
2
6 systemd-udevd.service, systemd-udevd-control.socket, systemd-udevd-
7 kernel.socket, systemd-udevd - Device event managing daemon
8
10 systemd-udevd.service
11 systemd-udevd-control.socket
13 systemd-udevd-kernel.socket
15 /usr/lib/systemd/systemd-udevd [--daemon] [--debug] [--children-max=]
17 [--exec-delay=] [--event-timeout=]
18 [--resolve-names=early|late|never]
19 [--version] [--help]
20
22 systemd-udevd listens to kernel uevents. For every event, systemd-udevd
23 executes matching instructions specified in udev rules. See udev(7).
24 The behavior of the daemon can be configured using udev.conf(5), its
26 command line options, environment variables, and on the kernel command
27 line, or changed dynamically with udevadm control.
28
30 -d, --daemon
31 Detach and run in the background.
32 -D, --debug
34 Print debug messages to standard error.
35 -c=, --children-max=
37 Limit the number of events executed in parallel.
38 -e=, --exec-delay=
40 Delay the execution of RUN instructions by the given number of
41 seconds. This option might be useful when debugging system crashes
42 during coldplug caused by loading non-working kernel modules.
43 -t=, --event-timeout=
45 Set the number of seconds to wait for events to finish. After this
46 time, the event will be terminated. The default is 180 seconds.
47 -N=, --resolve-names=
49 Specify when systemd-udevd should resolve names of users and
50 groups. When set to early (the default), names will be resolved
51 when the rules are parsed. When set to late, names will be resolved
52 for every event. When set to never, names will never be resolved
53 and all devices will be owned by root.
54 -h, --help
56 Print a short help text and exit.
57 --version
59 Print a short version string and exit.
60
62 Parameters starting with "rd." will be read when systemd-udevd is used
63 in an initrd.
64 udev.log_priority=, rd.udev.log_priority=
66 Set the log level.
67 udev.children_max=, rd.udev.children_max=
69 Limit the number of events executed in parallel.
70 udev.exec_delay=, rd.udev.exec_delay=
72 Delay the execution of RUN instructions by the given number of
73 seconds. This option might be useful when debugging system crashes
74 during coldplug caused by loading non-working kernel modules.
75 udev.event_timeout=, rd.udev.event_timeout=
77 Wait for events to finish up to the given number of seconds. This
78 option might be useful if events are terminated due to kernel
79 drivers taking too long to initialize.
80 net.ifnames=
82 Network interfaces are renamed to give them predictable names when
83 possible. It is enabled by default; specifying 0 disables it.
84 net.naming-scheme=
86 Network interfaces are renamed to give them predictable names when
87 possible (unless net.ifnames=0 is specified, see above). The names
88 are derived from various device metadata fields. Newer versions of
89 systemd-udevd.service take more of these fields into account,
90 improving (and thus possibly changing) the names used for the same
91 devices. With this kernel command line option it is possible to
92 pick a specific version of this algorithm. It expects a naming
93 scheme identifier as argument. Currently the following identifiers
94 are known: "v238", "v239", "v240" which each implement the naming
95 scheme that was the default in the indicated systemd version. In
96 addition, "latest" may be used to designate the latest scheme known
97 (to this particular version of systemd-udevd.service).
98 Note that selecting a specific scheme is not sufficient to fully
100 stabilize interface naming: the naming is generally derived from
101 driver attributes exposed by the kernel. As the kernel is updated,
102 previously missing attributes systemd-udevd.service is checking
103 might appear, which affects older name derivation algorithms, too.
104
106 udev.conf(5), udev(7), udevadm(8)
107systemd 241 SYSTEMD-UDEVD.SERVICE(8)