systemctl实用命令

查看服务是否开机启动

使用 systemctl list-unit-files 命令可查看服务的开机启动状态，状态说明如下：

• disabled：禁止开机启动
• enabled：开机启动
• static：与其他服务关联，无法单独设置启动状态

实用案例：

[root@localhost ~]# systemctl list-unit-files | grep chronyd
chronyd.service                               enabled 

[root@localhost ~]# systemctl list-unit-files | grep firewalld
firewalld.service                             disabled

查看服务当前状态

通过 systemctl status 服务名 命令查看服务运行状态，关键状态说明：

• active（running）：程序正在运行
• active（exited）：执行后正常退出，无持续运行程序
• active（waiting）：阻塞等待其他程序执行
• inactive（dead）：未启动状态

启动状态标识（vendor preset 字段）：

• inactive：服务关闭
• enabled：服务开机启动
• disabled：服务开机不启动
• static：启动项被管理
• failed：服务配置错误

实用案例：

[root@localhost ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)


[root@localhost ~]# systemctl status chronyd
● chronyd.service - NTP client/server
   Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2023-07-28 01:25:06 EDT; 1h 51min ago
     Docs: man:chronyd(8)
             man:chrony.conf(5)
  Process: 689 ExecStartPost=/usr/libexec/chrony-helper update-daemon (code=exited, status=0/SUCCESS)
  Process: 660 ExecStart=/usr/sbin/chronyd $OPTIONS (code=exited, status=0/SUCCESS)
 Main PID: 675 (chronyd)
   CGroup: /system.slice/chronyd.service
           └─675 /usr/sbin/chronyd

Jul 28 01:25:06 localhost.localdomain systemd[1]: Starting NTP client/server...
Jul 28 01:25:06 localhost.localdomain chronyd[675]: chronyd version 3.4 starting (+CMDMON +NTP +REFCLOCK +...BUG)
Jul 28 01:25:06 localhost.localdomain chronyd[675]: Frequency -7.503 +/- 0.603 ppm read from /var/lib/chro...rift
Jul 28 01:25:06 localhost.localdomain systemd[1]: Started NTP client/server.
Jul 28 01:25:14 localhost.localdomain chronyd[675]: Selected source 202.118.1.81
Jul 28 01:25:14 localhost.localdomain chronyd[675]: System clock wrong by 3926.276392 seconds, adjustment started
Jul 28 02:30:40 localhost.localdomain chronyd[675]: System clock was stepped by 3926.276392 seconds
Hint: Some lines were ellipsized, use -l to show in full.

其他实用小命令

服务控制基础命令

系统环境与服务配置命令

# 修改服务配置文件后重载配置
systemctl daemon-reload

# 设置服务开机自启动
systemctl enable postgresql.service

# 查询服务是否自启动
systemctl is-enabled postgresql.service

# 取消服务开机自启动
systemctl disable postgresql.service

# 检查服务是否正在运行
systemctl is-active application.service

# 检查服务是否启动失败
systemctl is-failed application.service

# 查看服务启动耗时
systemd-analyze blame

# 查看所有运行中的服务
systemctl list-units