Linux —— systemctl命令

Linux —— systemctl命令

Systemctl是一个系统管理守护进程、工具和库的集合，取代

systemctl -help

[root@localhost ~]# systemctl -help
systemctl [OPTIONS...] {COMMAND} ...

Query or send control commands to the systemd manager.

  -h --help           Show this help
     --version        Show package version
     --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

 

1、systemctl list-unit-files：列出所有可用单元

UNIT FILE 和 STATE两列，state：[static, disabled, enabled]

 

2、systemctl list-units：列出所有运行中单元

3、systemctl --failed：列出所有失败单元

4、systemctl is-enabled firewalld.service：检查某个单元是否启用（如firewalld.service）

启用返回enabled，禁用返回disabled

5、列出所有服务

• systemctl list-unit-files --type=service

筛选包含“free”的服务

• systemctl list-unit-files --type=service|grep free

列出所有系统挂载点：

• systemctl list-unit-files --type=mount

6、启动、重启、停止、重载服务以及检查服务状态

• # systemctl start httpd.service
• # systemctl restart httpd.service
• # systemctl stop httpd.service
• # systemctl reload httpd.service
• # systemctl status httpd.service

注意：当我们使用systemctl的start，restart，stop和reload命令时，终端不会输出任何内容，只有status命令可以打印输出。

7、激活服务并在开机时启用或禁用服务（即系统启动时自动启动postgresql.service服务）

• systemctl is-active postgresql.service
• systemctl enable postgresql.service（打印输出：Created symlink from /etc/systemd/system/multi-user.target.wants/postgresql.service to /usr/lib/systemd/system/postgresql.service.）
• systemctl disable postgresql.service（打印输出：Removed symlink /etc/systemd/system/multi-user.target.wants/postgresql.service.）

8、屏蔽或显示服务

• systemctl mask postgresql.service（终端输出：Created symlink from /etc/systemd/system/postgresql.service to /dev/null.）
• systemctl start postgresql.service（终端输出：Failed to start postgresql.service: Unit is masked.）
• systemctl unmask postgresql.service（终端输出：Removed symlink /etc/systemd/system/postgresql.service.）

9、杀死服务

• systemctl kill postgresql
• systemctl status postgresql（状态为failed，区别于stop服务的状态为inactive，---start启动）

10、挂载

• 列出所有系统挂载点：systemctl list-unit-files --type=mount

11. 挂载、卸载、重新挂载、重载系统挂载点并检查系统中挂载点状态 

# systemctl start tmp.mount

# systemctl stop tmp.mount

# systemctl restart tmp.mount

# systemctl reload tmp.mount

# systemctl status tmp.mount

12. 在启动时激活、启用或禁用挂载点（系统启动时自动挂载） 

# systemctl is-active tmp.mount

# systemctl enable tmp.mount

# systemctl disable tmp.mount

13. 在Linux中屏蔽（让它不能启用）或可见挂载点 

# systemctl mask tmp.mount

ln -s ‘/dev/null”/etc/systemd/system/tmp.mount’

# systemctl unmask tmp.mount

rm ‘/etc/systemd/system/tmp.mount’

 

 

参考：https://www.cnblogs.com/zhming26/p/6155201.html

 

查看某个服务是否

[root@localhost /]# systemctl status postgresql