systemctl은 기본적으로 root권한이 필요하기 때문에 아래와 같이 실행하며, systemd의 상태를 확인 및 제어가 가능하며
이 command를 이용하여, 각각의 service를 비롯하여 다양한 분석도 가능하다.
- 기본실행방법
$ sudo -s $ exit or $ sudo systemctl
systemctl - manual
https://www.freedesktop.org/software/systemd/man/systemctl.html
- systemd의 동작을 트리형태로 파악
$ systemctl status // systemd 의 전체 서비스의 실행되는 구조를 쉽게 파악
● raspberrypi
State: running
Jobs: 0 queued
Failed: 0 units
Since: Thu 1970-01-01 09:00:01 KST; 49 years 1 months ago
CGroup: /
├─user.slice
│ └─user-1000.slice
│ ├─session-c3.scope
│ │ ├─ 833 sshd: pi [priv]
│ │ ├─ 848 sshd: pi@pts/0
│ │ ├─ 851 -bash
│ │ ├─1090 systemctl status
│ │ └─1091 pager
상위에 적용되어지는 Option확인
https://www.freedesktop.org/software/systemd/man/systemctl.html#Options
- 개별 unit status 확인
$ systemctl status avahi-daemon.service //설정화면으로 들어감
● avahi-daemon.service - Avahi mDNS/DNS-SD Stack
Loaded: loaded (/lib/systemd/system/avahi-daemon.service; enabled; vendor preset: enabled)
Active: inactive (dead) since Sun 2019-02-17 01:44:46 KST; 2min 23s ago
Process: 1169 ExecStart=/usr/sbin/avahi-daemon -s (code=exited, status=0/SUCCESS)
Main PID: 1169 (code=exited, status=0/SUCCESS)
Status: "avahi-daemon 0.6.32 starting up."
......
$ systemctl is-enabled avahi-daemon.service
enabled
- units 의 종속성 확인
$ systemctl list-dependencies //default가 default.target default.target ● ├─acct.service ● ├─bootchart-done.service ● ├─bootchart.service ● ├─dphys-swapfile.service ● ├─lightdm.service ● ├─raspi-config.service ● ├─systemd-update-utmp-runlevel.service ● └─multi-user.target ● ├─acct.service ● ├─avahi-daemon.service ● ├─bluealsa.service ● ├─bootchart-done.service .... $ systemctl list-dependencies --all //모든 종속성을 확인가능 $ systemctl list-dependencies --after //default.target 기준으르 After (Unit 설정부분참조) $ systemctl list-dependencies --before //default.target 기준으르 Before $ systemctl list-dependencies raspi-config.service // 본인보고싶은 unit의 종속성확인
1.1 systemd의 unit의 제어
systemd의 command는 file(아래참조) 기반 과 systemd에서 생성된 unit(즉,실행되어 memory 존재),file 기반은 아래의 1,2번에 있는 unit들을 말한다.
더불어 systemd는 아래의 순서대로 찾지만 우선순위는 /etc가 높으므로, 최종제어는 /etc에서 한다
- /lib/systemd/system
- /etc/systemd/system
- unit 에 enable/disable 추가/제거 (file 기반)
$ systemctl enable avahi-daemon.service // /etc에 각 symbolic link 생성 Created symlink /etc/systemd/system/dbus-org.freedesktop.Avahi.service → /lib/systemd/system/avahi-daemon.service. Created symlink /etc/systemd/system/multi-user.target.wants/avahi-daemon.service → /lib/systemd/system/avahi-daemon.service. Created symlink /etc/systemd/system/sockets.target.wants/avahi-daemon.socket → /lib/systemd/system/avahi-daemon.socket. $ systemctl disable avahi-daemon.service // /etc에 각 symbolic link 제거 Removed /etc/systemd/system/dbus-org.freedesktop.Avahi.service. Removed /etc/systemd/system/multi-user.target.wants/avahi-daemon.service. Removed /etc/systemd/system/sockets.target.wants/avahi-daemon.socket. $ systemctl is-enabled avahi-daemon.service // 확인 enabled
// /lib 와 /etc wants 중심으로 기능확인
$ ls /lib/systemd/system/*wants
.....
/lib/systemd/system/multi-user.target.wants:
dbus.service systemd-logind.service
getty.target systemd-update-utmp-runlevel.service
systemd-ask-password-wall.path
....
/lib/systemd/system/sockets.target.wants:
dbus.socket systemd-journald.socket
systemd-initctl.socket systemd-udevd-control.socket
systemd-journald-audit.socket systemd-udevd-kernel.socket
systemd-journald-dev-log.socket
......
$ ls /etc/systemd/system/*wants
.....
/etc/systemd/system/multi-user.target.wants:
avahi-daemon.service machines.target rngd.service
busybox-klogd.service ofono.service systemd-networkd.service
busybox-syslog.service power-setup.service systemd-resolved.service
....
/etc/systemd/system/sockets.target.wants:
avahi-daemon.socket sshd.socket
...
- unit mask/unmask 제외 (file 기반)
만약 list-unit-files에는 검색은 되지만, enable이 제대로되지 않는다면, 이부분을 보자.
$ systemctl mask avahi-daemon.service // /lib 에 이미 존재하지만, /etc에서 막음 Created symlink /etc/systemd/system/avahi-daemon.service → /dev/null. $ systemctl unmask avahi-daemon.service // /etc에서 막은 것을 제거 (etc가 우선순위가 높음) Removed /etc/systemd/system/avahi-daemon.service $ systemctl list-unit-files | grep masked // mask 상태 확인 가능
- 개별 unit start/stop/restart/reload 동작제어 (memory 기반)
$ systemctl start avahi-daemon.service $ systemctl stop avahi-daemon.service $ systemctl restart avahi-daemon.service
- service enable /disable 한 후 동작확인 예 (timesyncd)
// service stop 한 후 disable 하여 다음 부팅시에도 미동작 $ systemctl stop systemd-timesyncd $ systemctl disable systemd-timesyncd // service enable 한 후 start $ systemctl enable systemd-timesyncd $ systemctl start systemd-timesyncd $ systemctl restart systemd-timesyncd //문제시 다시 restart //이 service 의 active or disable 확인 $ systemctl is-active systemd-timesyncd $ systemctl is-enabled systemd-timesyncd $ systemctl list-units --type service
1.2 Systemd 의 전체 Units 정보확인
일반적인 systemd의 unit 확인방법은 Memory에 있는 Unit(실행된 Unit)과 File에 존재하는 Unit로 검색이 가능하며,
세부옵션을 설정하여 다양하게 검색이 가능하다. .
- 세부옵션
- -t -type: Unit의 종류 (e.g service, target, timer, mount ...)
- -a -all: 모든 Unit의 정보를 보여준다.
- --state: Unit의 상태 입력 (e.g active, inactive, failed ... )
https://www.freedesktop.org/software/systemd/man/systemctl.html#Options
- list-units로 (in memory)
다양하게 검색이 가능하다
$ systemctl list-units or systemctl // default가 활성화된 Unit를 검색 및 device 분석 UNIT LOAD ACTIVE SUB DESCRIPTION proc-sys-fs-binfmt_misc.automount loaded active waiting Arbitrary Executable File F sys-devices-platform-soc-3f201000.serial-tty-ttyAMA0-hci0.device loaded active plugged /sys/devices/platform/soc/3 sys-devices-platform-soc-3f201000.serial-tty-ttyAMA0.device loaded active plugged /sys/devices/platform/soc/3 sys-devices-platform-soc-3f202000.mmc-mmc_host-mmc0-mmc0:aaaa-block-mmcblk0-mmcblk0p1.device loaded active plugged /sys/devices/platform/soc/3 sys-devices-platform-soc-3f202000.mmc-mmc_host-mmc0-mmc0:aaaa-block-mmcblk0-mmcblk0p2.device loaded active plugged /sys/devices/platform/soc/3 sys-devices-platform-soc-3f202000.mmc-mmc_host-mmc0-mmc0:aaaa-block-mmcblk0.device loaded active plugged /sys/devices/platform/soc/3 sys-devices-platform-soc-3f300000.mmc-mmc_host-mmc1-mmc1:0001-mmc1:0001:1-net-wlan0.device loaded active plugged /sys/devices/platform/soc/3 sys-devices-platform-soc-3f980000.usb-usb1-1\x2d1-1\x2d1.1-1\x2d1.1:1.0-net-eth0.device loaded active plugged SMSC9512/9514 Fast Ethernet sys-devices-platform-soc-soc:audio-bcm2835_alsa-sound-card0.device loaded active plugged /sys/devices/platform/soc/s sys-devices-virtual-block-ram0.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram1.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram10.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram11.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram12.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram13.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram14.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram15.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram2.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram3.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram4.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram5.device loaded active plugged /sys/devices/virtual/block/ sys-devices-virtual-block-ram6.device loaded active plugged /sys/devices/virtual/block/ .... LOAD = Reflects whether the unit definition was properly loaded. ACTIVE = The high-level unit activation state, i.e. generalization of SUB. SUB = The low-level unit activation state, values depend on unit type // UNIT 의 device들을 보면, 실제위치는 DESCRIPTION에 /sys filesystem 기반으로 구성되며, sys-devices 는 /sys/devices 이런식변경 // 최종 /sys의 device directory에서 uevent 확인 // 최종 /sys의 device directory에서 of_node/ 에서 각 속성확인
$ systemctl list-units | grep mount // mount 부분분석 -.mount loaded active mounted Root Mount home-root.mount loaded active mounted /home/root sys-fs-fuse-connections.mount loaded active mounted FUSE Control File System sys-kernel-config.mount loaded active mounted Kernel Configuration File System sys-kernel-debug.mount loaded active mounted Kernel Debug File System tmp.mount loaded active mounted Temporary Directory (/tmp) var-log.mount loaded active mounted /var/log var-volatile.mount loaded active mounted /var/volatile systemd-remount-fs.service loaded active exited Remount Root and Kernel File Systems .... $ find /etc/systemd/ -name *mount* // file mount 아무것도 없음 $ find /lib/systemd/ -name *mount* // file mount 부분분석 /lib/systemd/system/sys-fs-fuse-connections.mount /lib/systemd/system/sys-kernel-config.mount /lib/systemd/system/systemd-remount-fs.service /lib/systemd/system/machines.target.wants/var-lib-machines.mount /lib/systemd/system/sysinit.target.wants/sys-fs-fuse-connections.mount /lib/systemd/system/sysinit.target.wants/sys-kernel-config.mount /lib/systemd/system/sysinit.target.wants/dev-hugepages.mount /lib/systemd/system/sysinit.target.wants/dev-mqueue.mount /lib/systemd/system/sysinit.target.wants/sys-kernel-debug.mount /lib/systemd/system/dev-hugepages.mount /lib/systemd/system/umount.target /lib/systemd/system/var-lib-machines.mount /lib/systemd/system/remote-fs.target.wants/var-lib-machines.mount /lib/systemd/system/dev-mqueue.mount /lib/systemd/system/local-fs.target.wants/systemd-remount-fs.service /lib/systemd/system/local-fs.target.wants/tmp.mount /lib/systemd/system/tmp.mount /lib/systemd/system/sys-kernel-debug.mount /lib/systemd/systemd-remount-fs // binary 파일 // -.mount , home-root.mount , var-log.mount var-volatile.mount 는 상위에 존재하지 않음 // /lib/systemd/systemd-remount-fs 이 /etc/fstab 참조하여, 생성된 unit 이며, 이후 fsck로 filesystem 체크 $ cat /lib/systemd/system/systemd-remount-fs.service # SPDX-License-Identifier: LGPL-2.1+ # # This file is part of systemd. # # systemd is free software; you can redistribute it and/or modify it # under the terms of the GNU Lesser General Public License as published by # the Free Software Foundation; either version 2.1 of the License, or # (at your option) any later version. [Unit] Description=Remount Root and Kernel File Systems Documentation=man:systemd-remount-fs.service(8) Documentation=https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems DefaultDependencies=no Conflicts=shutdown.target After=systemd-fsck-root.service Before=local-fs-pre.target local-fs.target shutdown.target Wants=local-fs-pre.target ConditionPathExists=/etc/fstab [Service] Type=oneshot RemainAfterExit=yes ExecStart=/lib/systemd/systemd-remount-fs $ fdisk -l // 각 partition 확인 or $ systemd-mount --listhttps://www.freedesktop.org/software/systemd/man/systemd.html#
- 이외 세부검색방법
$ systemctl list-units -all // 모든 Unit 검색 (비활성화부분포함) or $ systemctl list-units -a // 모든 Unit 검색 (비활성화부분포함) $ systemctl list-units -t service // 활성화된 service unit만 검색 or $ systemctl list-units -type service // 활성화된 service unit만 검색 $ systemctl list-units -t target // 활성화된 target unit만 검색 (Unit 11개 종류가 있으므로 각각설정) $ systemctl list-units -t timer // 활성화된 timer unit만 검색 (Unit 11개 종류가 있으므로 각각설정) $ systemctl list-units -t service --state=inactive // 비활성화된 Unit의 Serivce만 검색 $ systemctl list-units --state=failed // Failed Unit 검색 or $ systemctl --failed // Failed Unit 검색
- list-sockets (in memory)
$ systemctl list-sockets // SOCKET의 LISTEN (Server)를 표시 (동작확인) (NETWORK 정보확인) $ systemctl list-units -t socket // 상위와 같이 UNIT의 status 만 확인
- list-timers (in memory)
$ systemctl list-timers // NEXT(다음동작) LEFT (남은시간) LAST (마지막실행) 동작확인 $ systemctl list-units -t timer // 상위와 같이 UNIT의 status 만 확인
- list-unit-files (in file)
$ systemctl list-unit-files UNIT FILE STATE proc-sys-fs-binfmt_misc.automount static -.mount generated boot.mount generated dev-hugepages.mount static dev-mqueue.mount static proc-fs-nfsd.mount static proc-sys-fs-binfmt_misc.mount static run-rpc_pipefs.mount static sys-fs-fuse-connections.mount static sys-kernel-config.mount static sys-kernel-debug.mount static systemd-ask-password-console.path static systemd-ask-password-plymouth.path static systemd-ask-password-wall.path static session-c1.scope transient session-c2.scope transient session-c3.scope transient acct.service generated alsa-restore.service static alsa-state.service static alsa-utils.service masked apply_noobs_os_config.service disabled apt-daily-upgrade.service static apt-daily.service static auth-rpcgss-module.service static autologin@.service enabled autovt@.service disabled .....
- service unit의 설정보기
$ systemctl show avahi-daemon.service Type=dbus Restart=no NotifyAccess=main RestartUSec=100ms TimeoutStartUSec=1min 30s TimeoutStopUSec=1min 30s RuntimeMaxUSec=infinity WatchdogUSec=0 WatchdogTimestampMonotonic=0 FailureAction=none PermissionsStartOnly=no RootDirectoryStartOnly=no RemainAfterExit=no GuessMainPID=yes MainPID=0 ControlPID=0 BusName=org.freedesktop.Avahi FileDescriptorStoreMax=0 NFileDescriptorStore=0 StatusText=avahi-daemon 0.6.32 starting up. StatusErrno=0 Result=success UID=4294967295 GID=4294967295 ...
https://wiki.archlinux.org/index.php/systemd
https://websetnet.com/ko/manage-systemd-services-and-units/
https://www.conory.com/note_linux/42241
https://www.freedesktop.org/wiki/Software/systemd/
http://linux.systemv.pe.kr/centos-7-systemd-%EC%9D%B4%ED%95%B4%ED%95%98%EA%B8%B0/
2. systemctl 이외의 설정
2.1 networkctl 설정
ifconfig 처럼 각각의 network의 정보를 확인 가능한 명령
- 물리적인 network 확인
$ networkctl --help
networkctl [OPTIONS...]
Query and control the networking subsystem.
-h --help Show this help
--version Show package version
--no-pager Do not pipe output into a pager
--no-legend Do not show the headers and footers
-a --all Show status for all links
Commands:
list [LINK...] List links
status [LINK...] Show link status
lldp [LINK...] Show LLDP neighbors
label Show current address label entries in the kernel
$ networkctl list // ifconfig 처럼 물리적인 network 연결상태확인 $ networkctl status -a // ifconfig 처럼 network IP 및 정보학인
networkctl (systemd-networkd)
https://www.freedesktop.org/software/systemd/man/networkctl.html#
https://www.freedesktop.org/software/systemd/man/systemd-networkd.service.html#
2.2 timedatectl 설정
시간에 관련된 설정으로 NTP를 비롯하여, Hardware 적인 시간인 RTC와 System Clock 와 지역 설정까지 가능하다.
- timedatectl 사용법
$ timedatectl --help
timedatectl [OPTIONS...] COMMAND ...
Query or change system time and date settings.
-h --help Show this help message
--version Show package version
--no-pager Do not pipe output into a pager
--no-ask-password Do not prompt for password
-H --host=[USER@]HOST Operate on remote host
-M --machine=CONTAINER Operate on local container
--adjust-system-clock Adjust system clock when changing local RTC mode
--monitor Monitor status of systemd-timesyncd
-p --property=NAME Show only properties by this name
-a --all Show all properties, including empty ones
--value When showing properties, only print the value
Commands:
status Show current time settings
show Show properties of systemd-timedated
set-time TIME Set system time
set-timezone ZONE Set system time zone
list-timezones Show known time zones
set-local-rtc BOOL Control whether RTC is in local time
set-ntp BOOL Enable or disable network time synchronization
systemd-timesyncd Commands:
timesync-status Show status of systemd-timesyncd
show-timesync Show properties of systemd-timesyncd
- timedatectl 기본상태확인
$ timedatectl // Time에 관련된 일반적인 상태확인 or $ timedatectl status Local time: Tue 2017-04-14 01:48:24 UTC // UTC Time +9이지만 현재 /etc/localtime을 사용하여 제대로 동작안됨 Universal time: Tue 2017-04-14 01:48:24 UTC // UTC Time RTC time: Tue 2017-04-14 01:48:23 // RTC기반으로 동작 Time zone: n/a (UTC, +0000) // UTC Time에 Time zone은 /etc/localtime으로 설정되어있음 (Seoul +9) System clock synchronized: no // 시간을 Sytem clock 과 동기화기능 NTP service: active // NTP Client로 timesyncd 이용 RTC in local TZ: no // RTC의 Timezon 사용여부 (timedatectl set-local-rtc 0)
- timezone 기능확인
$ timedatectl list-timezones // timezones list를 보여줌 //만약 동작하지 않는다면, timezone의 directory 확인 (/etc/localtime -> /usr/share/zoneinfo/Asia/Seoul) $ timedatectl set-timezone “Asia/Seoul” // 상위 /etc/localtime 링크변경
- timedatectl 날짜시간설정
$ timedatectl set-ntp 0 //변경시 주의사항.1 NTP설정(timedatectl set-ntp true)이면, set-time부분에서 에러발생 //변경시 주의사항.2 RTC에도 적용되므로 반드시 같이 확인 $ timedatectl set-time 2015-11-20 //날짜만 변경 $ timedatectl set-time 15:58:30 //시간만 변경 $ timedatectl set-time "2012-10-3018:17:16" //날짜시간동시변경
- Last login 정보지우기 (NTP/RTC 미사용시 이시간사용)
// 주의: Last Login Time 정보 Linux가 시스템 Time 설정가능 // 아래 파일은 binary가 있으므로 존재여부만 확인 $ cat /var/log/lastlog // Last Login 정보이지만, Binary이므로 깨짐 $ cat /var/log/utmp // last -f /var/log/utmp (picture of users logins at which terminals, logouts,) $ cat /var/log/wtmp // last -f /var/log/wtmp (utmp의 history) $ cat /var/log/btmp // last -f /var/log/btmp (records only failed login attempts.) // lastlogin 정보확인 $ who // 명령어로 본인 및 Last Login Time 확인 $ lastlog // last login 정보확인 (/var/log/lastlog 기반) // NTP Client Service Stop and Disable $ systemctl stop systemd-timesyncd $ systemctl disable systemd-timesyncd $ systemctl status systemd-timesyncd // 원하는 시간으로 변경 $ timedatectl set-time "2012-10-3018:17:16" // 주의: NTP 미사용 과 RTC 미사용한 후 시간설정이 되면 외부의 Device(GPS or 외부 RTC) 혹은 Build Time 에서 설정될 가능성이 높음 // lastlogin 정보삭제 $ lastlog -u root -C // last login user:root -C clear (lastlog가 /var/log/lastlog 기반) $ rm /var/log/lastlog $ rm /var/log/*tmp $ sync // HW Reset or Power On/Off
lastlog 정보
https://unixserveradmin.wordpress.com/2014/08/10/how-to-read-or-view-utmp-wtmp-and-btmp-files-in-linux/
- RTC 와 NTP 상태확인
// 상위설정상태 확인 가능, 아래 Timezone도 나와야함 $ timedatectl show LocalRTC=no // RTC on /off (timedatectl set-ntp 1 or 0) CanNTP=yes // NTP Client Service 존재여부 NTP=yes // NTP Service on / off (timedatectl set-ntp 1 or 0) NTPSynchronized=yes // NTP Server에 접속후 Sync 여부 TimeUSec=Tue 2017-07-02 10:38:38 KST // System 의 실제동작 시간 (date) RTCTimeUSec=Tue 2017-07-02 10:38:39 KST // RTC Time Sec (/proc/driver/rtc or /dev/rtc)
- NTP Server 연결상태확인
//확인시 주의사항 NTP설정(timedatectl set-ntp true)일 경우에만 확인 //NTP Server 동작확인 및 systemd-timesyncd service 설정확인 $ timedatectl timesync-status // NTP Packet 확인 (Network 문제로 접속못함) Server: (null) (time3.google.com) Poll interval: 0 (min: 32s; max 34min 8s) Packet count: 0 $ timedatectl timesync-status // NTP Packet 확인 (Network 문제로 접속한 후 주기적으로 Sync) Server: 216.239.35.0 (time1.google.com) Poll interval: 32s (min: 32s; max 34min 8s) Leap: normal Version: 4 Stratum: 1 Reference: GOOG Precision: 1us (-20) Root distance: 167us (max: 5s) Offset: -886.603ms Delay: 70.981ms Jitter: 0 Packet count: 1 Frequency: +0.000ppm $ timedatectl show-timesync // NTP 설정부분 확인 (systemd-timesyncd 설정확인필요) ......
- NTP Service 사용여부결정
//NTP 설정 부분 상위
$ timedatectl set-ntp true
$ timedatectl set-ntp false
- RTC 사용여부 결정
//RTC의 Local Time 적용여부 설정 $ timedatectl set-local-rtc 1 // /dev/rtc 사용하며, Local Time 적용여부 on (timedatectl status 확인) //이것으로 사용 $ timedatectl set-local-rtc 0 // /dev/rtc 사용하며, Local Time 적용여부 off
https://www.tecmint.com/set-time-timezone-and-synchronize-time-using-timedatectl-command/
https://www.freedesktop.org/software/systemd/man/timedatectl.html#
https://www.freedesktop.org/software/systemd/man/systemd-firstboot.html#
http://man7.org/linux/man-pages/man1/timedatectl.1.html
http://man7.org/linux/man-pages/man1/systemd-firstboot.1.html
- RTC 동작확인
$ ls /dev/rtc* // rtc->rtc0 link
/dev/rtc /dev/rtc0
$ cat /proc/driver/rtc
rtc_time : 16:31:36
rtc_date : 2017-03-13
alrm_time : 00:00:00
alrm_date : 1970-01-01
alarm_IRQ : no
alrm_pending : no
update IRQ enabled : no
periodic IRQ enabled : no
periodic IRQ frequency : 1
max user IRQ frequency : 64
24hr : yes
- RTC 와 Linux System 시간 동기화
$ hwclock -r // RTC Time 확인 $ hwclock -w // system 시간 -> /dev/rtc 시간저장 $ hwclock -s // /dev/rtc -> system 시간
AP의 경우 PMIC와 같이 사용할 경우, RTC를 PMIC와 함께 사용하는 경우가 있으므로, 반드시 관련 Kernel config와 관련 Datasheet 참조
http://man7.org/linux/man-pages/man8/hwclock.8.html
https://www.digi.com/resources/documentation/digidocs/90001546/reference/bsp/cc6/r_real_time_clock.htm
2.3 systemd에서 사용되어지는 ctrl 설정
그외에도 사용되어지는 ctrl command들이 존재하지만 경우에따라 다 지원하지는 않는것 같다.
사용한다면 아래의 Manual에서 확인하자
homectl
https://www.freedesktop.org/software/systemd/man/homectl.html#
hostnamectl
$ hostnamectl --help
hostnamectl [OPTIONS...] COMMAND ...
Query or change system hostname.
-h --help Show this help
--version Show package version
--no-ask-password Do not prompt for password
-H --host=[USER@]HOST Operate on remote host
-M --machine=CONTAINER Operate on local container
--transient Only set transient hostname
--static Only set static hostname
--pretty Only set pretty hostname
Commands:
status Show current hostname settings
set-hostname NAME Set system hostname
set-icon-name NAME Set icon name for host
set-chassis NAME Set chassis type for host
set-deployment NAME Set deployment environment for host
set-location NAME Set location for host
https://www.freedesktop.org/software/systemd/man/hostnamectl.html#loginctl
$ loginctl --help
loginctl [OPTIONS...] {COMMAND} ...
Send control commands to or query the login manager.
-h --help Show this help
--version Show package version
--no-pager Do not pipe output into a pager
--no-legend Do not show the headers and footers
--no-ask-password Don't prompt for password
-H --host=[USER@]HOST Operate on remote host
-M --machine=CONTAINER Operate on local container
-p --property=NAME Show only properties by this name
-a --all Show all properties, including empty ones
--value When showing properties, only print the value
-l --full Do not ellipsize output
--kill-who=WHO Who to send signal to
-s --signal=SIGNAL Which signal to send
-n --lines=INTEGER Number of journal entries to show
-o --output=STRING Change journal output mode (short, short-precise,
short-iso, short-iso-precise, short-full,
short-monotonic, short-unix, verbose, export,
json, json-pretty, json-sse, cat)
Session Commands:
list-sessions List sessions
session-status [ID...] Show session status
show-session [ID...] Show properties of sessions or the manager
activate [ID] Activate a session
lock-session [ID...] Screen lock one or more sessions
unlock-session [ID...] Screen unlock one or more sessions
lock-sessions Screen lock all current sessions
unlock-sessions Screen unlock all current sessions
terminate-session ID... Terminate one or more sessions
kill-session ID... Send signal to processes of a session
User Commands:
list-users List users
user-status [USER...] Show user status
show-user [USER...] Show properties of users or the manager
enable-linger [USER...] Enable linger state of one or more users
disable-linger [USER...] Disable linger state of one or more users
terminate-user USER... Terminate all sessions of one or more users
kill-user USER... Send signal to processes of a user
Seat Commands:
list-seats List seats
seat-status [NAME...] Show seat status
show-seat [NAME...] Show properties of seats or the manager
attach NAME DEVICE... Attach one or more devices to a seat
flush-devices Flush all device associations
terminate-seat NAME... Terminate all sessions on one or more seats
https://www.freedesktop.org/software/systemd/man/loginctl.html#userdbctl
https://www.freedesktop.org/software/systemd/man/userdbctl.html#
https://www.freedesktop.org/software/systemd/man/index.html