демон управления событиями устройства (Device event managing daemon)
Имя (Name)
systemd-udevd.service, systemd-udevd-control.socket, systemd-
udevd-kernel.socket, systemd-udevd - Device event managing daemon
Синопсис (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
]
Описание (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
.
Параметры (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 each RUN{program} parameter 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.
-s
, --timeout-signal=
Set the signal which systemd-udevd will send to forked off
processes after reaching event timeout. The setting can be
overridden at boot time with the kernel command line option
udev.timeout_signal=. Setting to SIGABRT
may be helpful in
order to debug worker timeouts. Defaults to SIGKILL
. Note
that setting the option on the command line overrides the
setting from the configuration file.
-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.
-h
, --help
Print a short help text and exit.
--version
Print a short version string and exit.
Командная строка ядра (Kernel command line)
Parameters prefixed with "rd." will be read when systemd-udevd
is
used in an initrd, those without will be processed both in the
initrd and on the host.
udev.log_level=, rd.udev.log_level=
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 each RUN{program} parameter 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.
udev.timeout_signal=, rd.udev.timeout_signal=
Specifies a signal that systemd-udevd will send to workers on
timeout. Note that kernel command line option overrides both
the setting in the configuration file and the one on the
program command line.
udev.blockdev_read_only, rd.udev.blockdev_read_only
If specified, mark all physical block devices read-only as
they appear. Synthetic block devices (such as loopback block
devices or device mapper devices) are left as they are. This
is useful to guarantee that the contents of physical block
devices remains unmodified during runtime, for example to
implement fully stateless systems, for testing or for
recovery situations where corrupted file systems shall not be
corrupted further through accidental modification.
A block device may be marked writable again by issuing the
blockdev --setrw
command, see blockdev(8) for details.
net.ifnames=
Network interfaces are renamed to give them predictable names
when possible. It is enabled by default; specifying 0
disables it.
net.naming-scheme=
Network interfaces are renamed to give them predictable names
when possible (unless net.ifnames=0 is specified, see above).
With this kernel command line option it is possible to pick a
specific version of this algorithm and override the default
chosen at compilation time. Expects one of the naming scheme
identifiers listed in systemd.net-naming-scheme(7), or
"latest" to select the latest scheme known (to this
particular version of systemd-udevd.service).
Note that selecting a specific scheme is not sufficient to
fully stabilize interface naming: the naming is generally
derived from driver attributes exposed by the kernel. As the
kernel is updated, previously missing attributes
systemd-udevd.service is checking might appear, which affects
older name derivation algorithms, too.
Смотри также (See also)
udev.conf(5), udev(7), udevadm(8)