# **systemctl** ## 说明 **systemctl命令** 是系统服务管理器指令，它实际上将 service 和 chkconfig 这两个命令组合到一起 ## 选项 ```markdown --system Connect to system manager -H --host=[USER@]HOST Operate on remote host -M --machine=CONTAINER Operate on local container -t --type=TYPE List units of a particular type --state=STATE List units with particular LOAD or SUB or ACTIVE state -p --property=NAME Show only properties by this name -a --all Show all loaded units/properties, including dead/empty ones. To list all units installed on the system, use the 'list-unit-files' command instead. -l --full Don't ellipsize unit names on output -r --recursive Show unit list of host and local containers --reverse Show reverse dependencies with 'list-dependencies' --job-mode=MODE Specify how to deal with already queued jobs, when queueing a new job --show-types When showing sockets, explicitly show their type -i --ignore-inhibitors When shutting down or sleeping, ignore inhibitors --kill-who=WHO Who to send signal to -s --signal=SIGNAL Which signal to send --now Start or stop unit in addition to enabling or disabling it -q --quiet Suppress output --no-block Do not wait until operation finished --no-wall Don't send wall message before halt/power-off/reboot --no-reload Don't reload daemon after en-/dis-abling unit files --no-legend Do not print a legend (column headers and hints) --no-pager Do not pipe output into a pager --no-ask-password Do not ask for system passwords --global Enable/disable unit files globally --runtime Enable unit files only temporarily until next reboot -f --force When enabling unit files, override existing symlinks When shutting down, execute action immediately --preset-mode= Apply only enable, only disable, or all presets --root=PATH Enable unit files in the specified root directory -n --lines=INTEGER Number of journal entries to show -o --output=STRING Change journal output mode (short, short-iso, short-precise, short-monotonic, verbose, export, json, json-pretty, json-sse, cat) --plain Print unit dependencies as a list instead of a tree Unit Commands: list-units [PATTERN...] List loaded units list-sockets [PATTERN...] List loaded sockets ordered by address list-timers [PATTERN...] List loaded timers ordered by next elapse start NAME... Start (activate) one or more units stop NAME... Stop (deactivate) one or more units reload NAME... Reload one or more units restart NAME... Start or restart one or more units try-restart NAME... Restart one or more units if active reload-or-restart NAME... Reload one or more units if possible, otherwise start or restart reload-or-try-restart NAME... Reload one or more units if possible, otherwise restart if active isolate NAME Start one unit and stop all others kill NAME... Send signal to processes of a unit is-active PATTERN... Check whether units are active is-failed PATTERN... Check whether units are failed status [PATTERN...|PID...] Show runtime status of one or more units show [PATTERN...|JOB...] Show properties of one or more units/jobs or the manager cat PATTERN... Show files and drop-ins of one or more units set-property NAME ASSIGNMENT... Sets one or more properties of a unit help PATTERN...|PID... Show manual for one or more units reset-failed [PATTERN...] Reset failed state for all, one, or more units list-dependencies [NAME] Recursively show units which are required or wanted by this unit or by which this unit is required or wanted Unit File Commands: list-unit-files [PATTERN...] List installed unit files enable NAME... Enable one or more unit files disable NAME... Disable one or more unit files reenable NAME... Reenable one or more unit files preset NAME... Enable/disable one or more unit files based on preset configuration preset-all Enable/disable all unit files based on preset configuration is-enabled NAME... Check whether unit files are enabled mask NAME... Mask one or more units unmask NAME... Unmask one or more units link PATH... Link one or more units files into the search path add-wants TARGET NAME... Add 'Wants' dependency for the target on specified one or more units add-requires TARGET NAME... Add 'Requires' dependency for the target on specified one or more units edit NAME... Edit one or more unit files get-default Get the name of the default target set-default NAME Set the default target Machine Commands: list-machines [PATTERN...] List local containers and host Job Commands: list-jobs [PATTERN...] List jobs cancel [JOB...] Cancel all, one, or more jobs Snapshot Commands: snapshot [NAME] Create a snapshot delete NAME... Remove one or more snapshots Environment Commands: show-environment Dump environment set-environment NAME=VALUE... Set one or more environment variables unset-environment NAME... Unset one or more environment variables import-environment [NAME...] Import all or some environment variables Manager Lifecycle Commands: daemon-reload Reload systemd manager configuration daemon-reexec Reexecute systemd manager System Commands: is-system-running Check whether system is fully running default Enter system default mode rescue Enter system rescue mode emergency Enter system emergency mode halt Shut down and halt the system poweroff Shut down and power-off the system reboot [ARG] Shut down and reboot the system kexec Shut down and reboot the system with kexec exit Request user instance exit switch-root ROOT [INIT] Change to a different root file system suspend Suspend the system hibernate Hibernate the system hybrid-sleep Hibernate and suspend the system ``` ## 实例 ```bash systemctl reboot # 重启系统 systemctl poweroff # 关闭系统，切断电源 systemctl halt # 关机 systemctl suspend # 暂停系统 systemctl hibernate # 休眠系统 systemctl hybrid-sleep # 让系统进入交互式休眠状态 systemctl rescue # 启动进入救援状态（单用户状态） systemctl list-units --type=service # 查看所有服务单元 systemd-analyze blame # 显示瀑布状的启动过程流 systemd-analyze critical-chain atd.service # 显示指定服务的启动流 localectl set-locale LANG=en_GB.utf8 localectl set-keymap en_GB # 设置本地化参数 timedatectl list-timezones # 显示所有可用的时区 # 设置当前时区 timedatectl set-timezone America/New_York timedatectl set-time YYYY-MM-DD timedatectl set-time HH:MM:SS loginctl list-sessions # 列出当前session loginctl list-users # 列出当前登录用户 loginctl show-user ruanyf # 列出显示指定用户的信息 systemctl is-active application.service # 显示某个 Unit 是否正在运行 systemctl is-failed application.service # 显示某个 Unit 是否处于启动失败状态 systemctl is-enabled application.service # 显示某个 Unit 服务是否建立了启动链接 systemctl daemon-reload # 重载所有修改过的配置文件 systemctl show httpd.service # 显示某个 Unit 的所有底层参数 systemctl set-property httpd.service CPUShares=500 # 设置某个 Unit 的指定属性 systemctl list-dependencies nginx.service # 列出一个unit的所有依赖 systemctl list-unit-files # 列出所有systemctl配置文件 systemctl list-unit-files --type=service # 列出指定类型的配置文件 systemctl list-unit-files --type=target # 查看当前系统的所有 Target systemctl list-dependencies multi-user.target # 查看一个 Target 包含的所有 Unit systemctl get-default # 查看启动时的默认 Target systemctl set-default multi-user.target # 设置启动时的默认 Target journalctl -k # 查看内核日志（不显示应用日志） journalctl -b -0 # 查看系统本次启动的日志 journalctl -b -1 # 查看上一次启动的日志（需更改设置） # 查看指定时间的日志 journalctl --since="2012-10-30 18:17:16" journalctl --since "20 min ago" journalctl --since yesterday journalctl --since "2015-01-10" --until "2015-01-11 03:00" journalctl --since 09:00 --until "1 hour ago" journalctl -n 20 # 显示尾部指定行数的日志 journalctl -f # 实时滚动显示最新日志 journalctl _PID=1 # 查看指定进程的日志 journalctl _UID=33 --since today # 查看指定用户的日志 journalctl -u nginx.service --since today # 查看某个 Unit 的日志 journalctl -u nginx.service -f # 实时滚动显示某个 Unit 的最新日志 journalctl -u nginx.service -u php-fpm.service --since today # 合并显示多个 Unit 的日志 journalctl -p err -b # 查看指定优先级（及其以上级别）的日志，共有8级 0: emerg 1: alert 2: crit 3: err 4: warning 5: notice 6: info 7: debug journalctl --no-pager # 日志默认分页输出，--no-pager 改为正常的标准输出 journalctl -b -u nginx.service -o json # 以 JSON 格式（单行）输出 journalctl -b -u nginx.serviceqq -o json-pretty # 以 JSON 格式（多行）输出，可读性更好 journalctl --disk-usage # 显示日志占据的硬盘空间 journalctl --vacuum-size=1G # 指定日志文件占据的最大空间 journalctl --vacuum-time=1years # 指定日志文件保存多久 ```