systemctl

systemctl start/status/stop/restart/enable/disable/mask/unmask/is-active/is-enabled xxx
systemctl
systemctl list-units  [--type=service --all]
systemctl list-unit-files 
systemctl list-sockets
​
#追踪unit的依赖
systemctl list-dependencies sshd  # 查看sshd服务的依赖
sshd.service
● ├─-.mount
● ├─system.slice
● └─sysinit.target
●   ├─apparmor.service
●   ├─blk-availability.service
●   ├─dev-hugepages.mount
●   ├─dev-mqueue.mount
●   ├─keyboard-setup.service
●   ├─kmod-static-nodes.service
●   ├─lvm2-lvmetad.socket
●   ├─lvm2-lvmpolld.socket
●   ├─lvm2-monitor.service
●   ├─open-iscsi.service
●   ├─plymouth-read-write.service
●   ├─plymouth-start.service
●   ├─proc-sys-fs-binfmt_misc.automount
●   ├─setvtrgb.service
●   ├─sys-fs-fuse-connections.mount
●   ├─sys-kernel-config.mount
●   ├─sys-kernel-debug.mount
●   ├─systemd-ask-password-console.path
●   ├─systemd-binfmt.service
​
systemctl list-dependencies --reverse plymouth-read-write.service  | grep ssh # 反向查找依赖某unit的unit
●   ├─ssh.service