UDEVADM(8) udevadm UDEVADM(8) (NAME) udevadm - udev (SYNOPSIS) udevadm [--debug] [--version] [--help] udevadm info [options] [devpath] udevadm trigger [options] [devpath] udevadm settle [options] udevadm control option udevadm monitor [options] udevadm test [options] devpath udevadm test-builtin [options] command devpath udevadm verify [options...] [file...] udevadm wait [options] device|syspath udevadm lock [options] command (DESCRIPTION) udevadm . systemd-udevd . (OPTIONS) -d, --debug (stderr). udevadm test udevadm test-builtin . -h, --help . udevadm info [options] [devpath|file|unit] udev . . ( /dev/ ) sys ( /sys/ ) systemd ( ".device" systemd.device(5) ). -q, --query=TYPE . TYPE : name symlink path property all. --property=NAME --query=property . . . 250 . --value --query=property "=" . -x/--export -P/--export-prefix . 250 . -p, --path=DEVPATH /sys/ [/sys/]/class/block/sda. /sys/ . udevadm info --path=/class/block/sda udevadm info /sys/class/block/sda . -n, --name=FILE (symlink) [/dev/]/sda. /dev/ . udevadm info --name=sda udevadm info /dev/sda . -r, --root name symlink. -a, --attribute-walk sysfs udev . sysfs udev . JSON ( --json= ). JSON JSON-SEQ (RFC7464). (: jq[1] JSON-SEQ --seq .) -t, --tree sysfs. sysfs . . . 251 . -x, --export /. (single quotes) . --query=property --device-id-of-file=FILE . -P, --export-prefix=NAME . --export . -d, --device-id-of-file=FILE / (major/minor) . . -e, --export-db udev. -c, --cleanup-db udev. -w[SECONDS], --wait-for-initialization[=SECONDS] . SECONDS . 243 . --subsystem-match[=SUBSYSTEM], --subsystem-nomatch[=SUBSYSTEM] --export-db . 255 . --attr-match[=FILE[=VALUE]], --attr-nomatch[=FILE[=VALUE]] --export-db . 255 . --property-match[=KEY=VALUE] --export-db . 255 . --tag-match[=TAG] --export-db (tag) . 255 . --sysname-match[=NAME] --export-db "/sys" . 255 . --name-match[=NAME] --export-db "/dev" . 255 . --parent-match[=NAME] --export-db . 255 . --initialized-match, --initialized-nomatch --export-db . 255 . --json=MODE JSON. : "short" ( ) "pretty" ( ) "off" ( JSON ). -h, --help . --no-pager (pager) . . : . udevadm info +-------------------+---------------------------+ | | | +-------------------+---------------------------+ |"P:" | | | | | | | /sys/ | +-------------------+---------------------------+ |"M:" | | | | | | | /sys/ ( | | | | | | "P:") | +-------------------+---------------------------+ |"R:" | | | | | | | /sys/ ( | | | | | | | | | | | | "P:") | +-------------------+---------------------------+ |"J:" | | | | | +-------------------+---------------------------+ |"U:" | | | | | +-------------------+---------------------------+ |"B:" | | | | | +-------------------+---------------------------+ |"T:" | | | | | | | | | | | | | | +-------------------+---------------------------+ |"D:" | | | | / | | | (major/minor) | | | | | | | +-------------------+---------------------------+ |"I:" | | | | | +-------------------+---------------------------+ |"N:" | | | | | | | | +-------------------+---------------------------+ |"L:" | | | | | | | | | | | | | | +-------------------+---------------------------+ |"S:" | | | | | | | | | | | +-------------------+---------------------------+ |"Q:" | | | | | | | | | | (DISKSEQ) | +-------------------+---------------------------+ |"V:" | | | | | +-------------------+---------------------------+ |"E:" | | | | | +-------------------+---------------------------+ udevadm trigger [options] [devpath|file|unit] . (coldplug) . . info . -v, --verbose (trigger) . -n, --dry-run ( ). -q, --quiet . 248 . -t, --type=TYPE . : "all" "devices" "subsystems". "devices" . -c, --action=ACTION . : "add" "remove" "change" "move" "online" "offline" "bind" "unbind". "help" . "change" . --prioritized-subsystem=SUBSYSTEM[,SUBSYSTEM...] . . --prioritized-subsystem=block,net . . --prioritized-subsystem=block --prioritized-subsystem=net --prioritized-subsystem=block,net . 251 . -s, --subsystem-match=SUBSYSTEM . . OR . -S, --subsystem-nomatch=SUBSYSTEM . . AND . -a, --attr-match=ATTRIBUTE=VALUE sysfs . . sysfs . AND . -A, --attr-nomatch=ATTRIBUTE=VALUE sysfs . . sysfs . AND . -p, --property-match=PROPERTY=VALUE . . OR . -g, --tag-match=TAG . AND . -y, --sysname-match=NAME ( ) /sys/ PATH . . OR NAME . --name-match=NAME . OR . 218 . -b, --parent-match=SYSPATH . OR . --initialized-match, --initialized-nomatch --initialized-match systemd-udevd . --initialized-nomatch systemd-udevd . udev . << >> . --initialized-nomatch . . udev ( "ATTRS" "IMPORT{parent}" udev(7) ) . 251 . -w, --settle . udevadm settle . udevadm settle . . 238 . --uuid (synthetic) UUID . UUID ( ). UUID uevent ( "SYNTH_UUID=" ) . 249 . --wait-daemon[=SECONDS] uevent systemd-udevd . (timeout) . . udevadm control --ping udevadm trigger . 241 . -h, --help . sys . /dev/ /sys/ . udevadm settle [options] udev . -t, --timeout=SECONDS . . 0 . 0 . -E, --exit-if-exists=FILE . -h, --help . systemd-udev- settle.service(8) . udevadm control option udev. -e, --exit systemd-udevd . --timeout . systemd-udevd.service Restart=always (restart) systemd-udevd . systemd-udevd.service : systemctl stop systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd.service -l, --log-level=value (log level) systemd-udevd. syslog : emerg alert crit err warning notice info debug. -s, --stop-exec-queue systemd-udevd . . -S, --start-exec-queue systemd-udevd . -R, --reload systemd-udevd . . -p, --property=KEY=value . -m, --children-max=value systemd-udevd . 0 . --ping systemd-udevd . systemd-udevd . 241 . -t, --timeout=seconds systemd-udevd. --load-credentials (credentials) : udev.conf.* udev.conf(5) . . : udev.conf.50-foobar /run/udev/udev.conf.d/50-foobar.conf . 256 . udev.rules.* udev(7) . . : udev.rules.50-foobar /run/udev/rules.d/50-foobar.rules . 256 . --reload . systemd-udevd --reload udev systemd-udevd . 256 . -h, --help . udevadm monitor [options] uevent udev devpath . uevent udev . -k, --kernel uevent . -u, --udev udev . -p, --property . -s, --subsystem-match=string[/string] uevent udev [/]. . OR . -t, --tag-match=string udev (tag). udev . OR . -h, --help . udevadm test [options] [devpath|file|unit] udev . -a, --action=ACTION . : "add" "remove" "change" "move" "online" "offline" "bind" "unbind". "help" . "add" . -N, --resolve-names=early|late|never udevadm (resolve) . early () . late . never root . 209 . -h, --help . udevadm test-builtin [options] command [devpath|file|unit] (built-in) COMMAND DEVPATH . -a, --action=ACTION . : "add" "remove" "change" "move" "online" "offline" "bind" "unbind". "help" . "add" . 250 . -h, --help . --version . udevadm verify [options] [file] ... udev. . udev udev/rules.d udev . 0 udev . -N, --resolve-names=early|never udevadm . early () . never . 254 . --root=PATH udev udev/rules.d PATH . 254 . --no-summary . 254 . --no-style . udev 0 . 254 . -h, --help . udevadm wait [options] [device|syspath] ... systemd-udevd. "/dev/" "/sys/" : "/dev/sda" "/dev/disk/by-path/pci-0000:3c:00.0-nvme-1-part1" "/sys/devices/pci0000:00/0000:00:1f.6/net/eth0" "/sys/class/net/eth0". . systemd-udevd () . -t, --timeout=SECONDS . "infinity" () . 251 . --initialized=BOOL systemd-udevd . true . false . udev false . << >> . 251 . --removed . --initialized= . 251 . --settle udev systemd-udevd . 251 . -h, --help . udevadm lock [options] [command] ... udevadm lock Locking Block Device Access[2] () ( ) . udevadm lock . systemd-udevd.service(8) ( ) (probe) . --lock sfdisk(8) . --device= --backing= . --device=DEVICE, -d DEVICE . ( --backing=) . <<>> . / . . ( --backing= .) 251 . --backing=PATH, -b PATH --device= . / --device= . 251 . --timeout=SECS, -t SECS . systemd.time(7) . . "infinity" () . . 251 . --print, -p . <<>> . ( ). --device= --backing= <<>> . 251 . -h, --help . (INITIALIZED DEVICES) udev - "remove" -- ( udev ). "remove" ( udev ) . udev sd-device API ( ) . (EXAMPLES) . () systemd-udevd (superblock) : # udevadm lock --device=/dev/sda1 mkfs.ext4 /dev/sda1 . RAID : # udevadm lock --device=/dev/sda1 --device=/dev/sdb1 mkfs.btrfs /dev/sda1 /dev/sdb1 . systemd-udevd : # udevadm lock -d /dev/sda1 dd if=fs.raw of=/dev/sda1 (SEE ALSO) udev(7), systemd-udevd.service(8) (NOTES) 1. jq https://jqlang.github.io/jq/manual 2. Locking Block Device Access https://systemd.io/BLOCK_DEVICE_LOCKING systemd 257.13 UDEVADM(8)