【Linux】2、systemd、journalctl 超详细介绍
文章目录
- 一、背景
- 二、系统管理
-
- 2.1 systemctl
-
- 2.1.1 State: degraded
- 2.2 systemd-analyze
- 2.3 hostnamectl
- 2.4 localectl
- 2.5 timedatectl
- 2.6 loginctl
- 三、Unit
-
- 3.1 含义
- 3.2 展示
- 3.3 状态
- 3.4 管理
- 3.5 依赖关系
- 四、Unit 的配置文件
-
- 4.1 配置文件层级
- 4.2 配置文件的状态
- 4.3 配置文件的格式
- 4.4 配置文件的区块
-
- 4.4.1 [Unit]
- 4.4.2 [Install]
- 4.4.3 [Service]
- 五、Target 是 Unit 组
- 六、journalctl
- 七、启动
-
- 7.1 开机启动
- 7.2 启停服务
官网
systemd 中文手册
System 命令与实战-阮一峰
一、背景
历史上，Linux 的启动一直采用init进程。但有如下两个缺点
- 启动时间长。init进程是串行启动，只有前一个进程启动完，才会启动下一个进程。
- 启动脚本复杂。init进程只是执行启动脚本，不管其他事情。脚本需要自己处理各种情况，这往往使得脚本变得很长。
/etc/init.d/apache2 start
service apache2 start
Systemd 就是为了解决这些问题而诞生的。它的设计目标是，为系统的启动和管理提供一套完整的解决方案。
使用了 Systemd，就不需要再用init了。Systemd 取代了initd，成为系统的第一个进程（PID 等于 1），其他进程都是它的子进程。
二、系统管理
2.1 systemctl
systemctl 是 Systemd 的主命令，用于管理系统。
systemctl reboot # 重启
systemctl poweroff # 关闭系统，切断电源
systemctl halt # CPU停止工作
systemctl suspend # 暂停系统
systemctl hibernate # 让系统进入冬眠状态
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）
2.1.1 State: degraded
当 systemctl status 命令输出 State: degraded 时，意味着有些服务无法启动
- 可通过
systemctl查看所有服务 - 可通过
systemctl --failed或systemctl | grep fail查看所有失败的服务
2.2 systemd-analyze
查看启动耗时
# 查看启动耗时
root@node:~# systemd-analyze
Startup finished in 8.149s (kernel) + 10.497s (userspace) = 18.646s
graphical.target reached after 10.416s in userspace
# 查看每个服务的启动耗时
root@node:~# systemd-analyze blame
1.306s app-docker.service
1.008s dev-loop1.device
920ms systemd-timesyncd.service
# 显示瀑布状的启动过程流
root@node:~# systemd-analyze critical-chain
The time when unit became active or started is printed after the "@" character.
The time the unit took to start is printed after the "+" character.
graphical.target @10.416s
└─multi-user.target @10.416s
└─entry-app.service @4.001s +6.413s
└─entry-sys.service @2.651s +1.330s
└─basic.target @2.614s
└─sockets.target @2.598s
└─app-docker.socket @6.073s +77ms
└─sysinit.target @2.488s
└─systemd-timesyncd.service @5.070s +920ms
└─systemd-tmpfiles-setup.service @1.916s +28ms
└─systemd-journal-flush.service @1.336s +463ms
└─systemd-remount-fs.service @936ms +347ms
└─systemd-journald.socket @578ms
└─system.slice @268ms
└─-.slice @268ms
# 显示指定服务的启动流
root@node:~# systemd-analyze critical-chain app-docker.socket
The time when unit became active or started is printed after the "@" character.
The time the unit took to start is printed after the "+" character.
app-docker.socket +77ms
└─sysinit.target @2.488s
└─systemd-timesyncd.service @5.070s +920ms
└─systemd-tmpfiles-setup.service @1.916s +28ms
└─systemd-journal-flush.service @1.336s +463ms
└─systemd-remount-fs.service @936ms +347ms
└─systemd-journald.socket @578ms
└─system.slice @268ms
└─-.slice @268ms
2.3 hostnamectl
查看当前主机的信息
root@node:~# hostnamectl -h
hostnamectl [OPTIONS...] COMMAND ...
Query or change system 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
Options:
-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
See the hostnamectl(1) man page for details.
root@node:~# hostnamectl status
Static hostname: node
Icon name: computer
Machine ID: xxx
Boot ID: yyy
Operating System: Ubuntu 20.04.4 LTS
Kernel: Linux 4.30
Architecture: arm64
hostnamectl # 显示当前主机的信息
hostnamectl set-hostname rhel7 # 设置主机名。
2.4 localectl
查看本地化设置
# 查看本地化设置
root@node:~# localectl
System Locale: LANG=C
LC_CTYPE=C.UTF-8
LC_NUMERIC=C.UTF-8
LC_TIME=C.UTF-8
LC_COLLATE=C.UTF-8
LC_MONETARY=C.UTF-8
LC_MESSAGES=C.UTF-8
LC_PAPER=C.UTF-8
LC_NAME=C.UTF-8
LC_ADDRESS=C.UTF-8
LC_TELEPHONE=C.UTF-8
LC_MEASUREMENT=C.UTF-8
LC_IDENTIFICATION=C.UTF-8
VC Keymap: n/a
X11 Layout: n/a
# 设置本地化参数
localectl set-locale LANG=en_GB.utf8
localectl set-keymap en_GB
2.5 timedatectl
查看当前时区
# 查看当前时区设置
root@node:~# timedatectl
Local time: Sat 2023-04-22 23:26:11 CST
Universal time: Sat 2023-04-22 15:26:11 UTC
RTC time: Sat 2023-04-22 15:26:12
Time zone: localtime (CST, +0800)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no
# 显示所有可用的时区
root@node:~# timedatectl list-timezones
Africa/Abidjan
Africa/Accra
Africa/Addis_Ababa
Africa/Algiers
# 设置当前时区
sudo timedatectl set-timezone America/New_York
sudo timedatectl set-time YYYY-MM-DD
sudo timedatectl set-time HH:MM:SS
2.6 loginctl
查看当前登录的用户
# 列出当前session
root@node:~# loginctl list-sessions
No sessions.
# 列出当前登录用户
root@node:~# loginctl list-users
No users.
# 列出显示指定用户的信息
root@node:~# loginctl show-user userabc
Failed to look up user userabc: No such process
三、Unit
3.1 含义
Systemd 可以管理所有系统资源。不同的资源统称为 Unit（单位）。Unit 共12种。systemctl list-units 可查当前系统的所有 Unit 。
Service unit：系统服务
Target unit：多个 Unit 构成的一个组
Device Unit：硬件设备
Mount Unit：文件系统的挂载点
Automount Unit：自动挂载点
Path Unit：文件或路径
Scope Unit：不是由 Systemd 启动的外部进程
Slice Unit：进程组
Snapshot Unit：Systemd 快照，可以切回某个快照
Socket Unit：进程间通信的 socket
Swap Unit：swap 文件
Timer Unit：定时器
3.2 展示
root@node:~# systemctl list-units
UNIT >
sys-devices-platform-50108000.ethernet-net-eth1.device >
sys-devices-platform-5010c000.ethernet-net-eth0.device >
sys-devices-platform-50118000.serial-tty-ttyS0.device
# 列出所有Unit，包括没有找到配置文件的或者启动失败的
root@node:~# systemctl list-units --all
UNIT >
proc-sys-fs-binfmt_misc.automount >
dev-disk-by\x2did-ata\x2dWDC_WD20SPZX\x2d00UA7T0_WD\x2dWX92A52DRRNX.device >
dev-disk-by\x2did-ata\x2dWDC_WD20SPZX\x2d00UA7T0_WD\x2dWX92A52DRRNX\x2dpart1.device >
dev-disk-by\x2did-mmc\x2d88A19B_0x5b97d9a0.device
# 列出所有没有运行的 Unit
root@node:~# systemctl list-units --all --state=inactive
UNIT LOAD ACTIVE SUB DESCRIPTION >
proc-sys-fs-binfmt_misc.automount loaded inactive dead Arbitrary Executable File Formats File System>
proc-sys-fs-binfmt_misc.mount loaded inactive dead Arbitrary Executable File Formats File System>
sys-kernel-config.mount loaded inactive dead Kernel Configuration File System >
● auditd.service not-found inactive dead auditd.service
# 列出所有加载失败的 Unit
root@node:~# systemctl list-units --failed
UNIT LOAD ACTIVE SUB DESCRIPTION
● app-start-freyr.service loaded failed failed run freyr
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.
1 loaded units listed.
# 列出所有正在运行的、类型为 service 的 Unit
root@node:~# systemctl list-units --type=service
UNIT LOAD ACTIVE SUB DESCRIPTION >
app-containerd.service loaded active running containerd container runtime >
app-deh7.service loaded activating auto-restart deh7 >
app-devicefind.service loaded active running DeviceFind >
app-docker.service loaded active running Docker Application Container Engine
root@node:~/PKG# systemctl list-unit-files
UNIT FILE STATE VENDOR PRESET
proc-sys-fs-binfmt_misc.automount static enabled
dev-hugepages.mount static enabled
dev-mqueue.mount static enabled
proc-fs-nfsd.mount static enabled
proc-sys-fs-binfmt_misc.mount disabled enabled
3.3 状态
systemctl status命令用于查看系统状态和单个 Unit 的状态。
# 显示系统状态
root@node:~/PKG# systemctl status
● node
State: running
Jobs: 0 queued
Failed: 0 units
Since: Sat 2023-04-22 18:32:48 CST; 14h ago
CGroup: /
├─init.scope
│ ├─ 1 /lib/systemd/systemd
│ └─254 haveged -w 1024 -v 1 -F
└─system.slice
├─app-start-pastur.service
│ ├─701 /bin/sh /home/node/Applications/pastur.app.dpk.mnt/run.sh
│ └─703 /home/node/Applications/pastur.app.dpk.mnt/pastur -config /home/node/Applications/pastur.app.dpk.mnt/config.toml
├─app-deh7.service
│ └─927 /home/node/Applications/deh7.app.dpk.mnt/deh7
├─app-start-aaa.service
│ ├─834 /bin/sh /home/node/Applications/aaa.app.dpk.mnt/run.sh
│ └─840 /home/node/Applications/aaa.app.dpk.mnt/aaa
├─systemd-timesyncd.service
│ └─591 /lib/systemd/systemd-timesyncd
# 显示单个 Unit 的状态
root@node:~/PKG# systemctl status app-start-abc.service
● app-start-abc.service - run abc
Loaded: loaded (/run/systemd/transient/app-start-abc.service; transient)
Transient: yes
Active: active (running) since Sat 2023-04-22 18:32:58 CST; 14h ago
Main PID: 1261 (run.sh)
Tasks: 12 (limit: 3093)
Memory: 33.6M
CGroup: /system.slice/app-start-abc.service
├─1261 /bin/sh /home/node/Applications/abc.app.dpk.mnt/run.sh
└─1263 ./abc
Apr 23 09:07:58 node run.sh[1263]: time="2023-04-23T09:07:58+08:00" level=info msg="vehicle similarity vacuum start at: 2023-04-23 09:07:58.474237963 +0800 CST m=+52500.093>
Apr 23 09:07:58 node run.sh[1263]: time="2023-04-23T09:07:58+08:00" level=info msg="vehicle similarity vacuum end at: 2023-04-23 09:07:58.474237963 +0800 CST m=+52500.09306>
Apr 23 09:08:58 node run.sh[1263]: time="2023-04-23T09:08:58+08:00" level=info msg="vehicle similarity vacuum start at: 2023-04-23 09:08:58.473939125 +0800 CST m=+52560.092>
Apr 23 09:08:58 node run.sh[1263]: time="2023-04-23T09:08:58+08:00" level=info msg="vehicle similarity vacuum end at: 2023-04-23 09:08:58.473939125 +0800 CST m=+52560.09276>
Apr 23 09:09:58 node run.sh[1263]: time="2023-04-23T09:09:58+08:00" level=info msg="vehicle similarity vacuum start at: 2023-04-23 09:09:58.474018147 +0800 CST m=+52620.092>
Apr 23 09:09:58
# 显示远程主机的某个 Unit 的状态
root@node:~/PKG# systemctl -H 192.168.100.31 status app-start-abc.service
[email protected]'s password:
● app-start-abc.service - run abc
Loaded: loaded (/run/systemd/transient/app-start-abc.service; transient)
Transient: yes
Active: activating (auto-restart) (Result: exit-code) since Sun 2023-04-23 09:15:08 CST; 37ms ago
Process: 1380597 ExecStart=/home/node/Applications/abc.app.dpk.mnt/run.sh (code=exited, status=2)
Main PID: 1380597 (code=exited, status=2)
除了status命令，systemctl还提供了三个查询状态的简单方法，主要供脚本内部的判断语句使用。
# 显示某个 Unit 是否正在运行
root@node:~/PKG# systemctl is-active app-start-abc.service
active
# 显示某个 Unit 是否处于启动失败状态
root@node:~/PKG# systemctl is-failed app-start-abc.service
active
# 显示某个 Unit 服务是否建立了启动链接
root@node:~/PKG# systemctl is-enabled app-start-abc.service
transient
3.4 管理
对于用户来说，最常用的是下面这些命令，用于启动和停止 Unit（主要是 service）。
# 显示某个 Unit 的所有底层参数
root@node:~/PKG# systemctl show app-start-abc.service
Restart=no
NotifyAccess=none
RestartUSec=100ms
TimeoutStartUSec=1min 30s
TimeoutStopUSec=30s
TimeoutAbortUSec=30s
RuntimeMaxUSec=infinity
WatchdogUSec=0
WatchdogTimestampMonotonic=0
RootDirectoryStartOnly=no
RemainAfterExit=no
GuessMainPID=yes
MainPID=0
ControlPID=0
FileDescriptorStoreMax=0
NFileDescriptorStore=0
StatusErrno=0
Result=success
ReloadResult=success
CleanResult=success
UID=[not set]
systemctl restart apache.service # 重启一个服务
systemctl start apache.service # 立即启动一个服务
systemctl stop apache.service # 立即停止一个服务(会导致找不到 unit files，从而无法 systemctl start, 而只能 reboot 才能再拉起服务)
systemctl kill apache.service # 杀死一个服务的所有子进程
root@node:~# systemctl reload app-start-abc.service # 重新加载一个服务的配置文件'
Failed to reload app-start-abc.service: Job type reload is not applicable for unit app-start-abc.service.
systemctl daemon-reload # 重载所有修改过的配置文件
root@node:~# systemctl show -p CPUShares app-start-abc.service # 显示某个 Unit 的指定属性的值
CPUShares=[not set]
root@node:~# systemctl set-property app-start-abc.service CPUShares=500 # 设置某个 Unit 的指定属性
root@node:~# systemctl show -p CPUShares app-start-abc.service
CPUShares=500
3.5 依赖关系
Unit 之间存在依赖关系：A 依赖于 B，就意味着 Systemd 在启动 A 的时候，同时会去启动 B。
# 列出一个 Unit 的所有依赖
root@node:~# systemctl list-dependencies
default.target
● ├─display-manager.service
● ├─systemd-update-utmp-runlevel.service
● └─multi-user.target
● ├─dbus.service
● ├─delinux-entry-app.service
● ├─delinux-entry-sys.service
● ├─systemd-ask-password-wall.path
● ├─systemd-networkd.service
● ├─systemd-resolved.service
● ├─systemd-update-utmp-runlevel.service
● ├─systemd-user-sessions.service
● ├─basic.target
● │ ├─tmp.mount
● │ ├─paths.target
● │ ├─slices.target
● │ │ ├─-.slice
● │ │ └─system.slice
● │ ├─sockets.target
● │ │ ├─dbus.socket
● │ │ ├─systemd-initctl.socket
● │ │ ├─systemd-journald-audit.socket
● │ │ ├─systemd-journald-dev-log.socket
● │ │ ├─systemd-journald.socket
● │ │ ├─systemd-udevd-control.socket
● │ │ └─systemd-udevd-kernel.socket
● │ ├─sysinit.target
● │ │ ├─dev-hugepages.mount
● │ │ ├─dev-mqueue.mount
● │ │ ├─kmod-static-nodes.service
● │ │ ├─proc-sys-fs-binfmt_misc.automount
● │ │ ├─sys-fs-fuse-connections.mount
● │ │ ├─sys-kernel-config.mount
● │ │ ├─sys-kernel-debug.mount
● │ │ ├─sys-kernel-tracing.mount
● │ │ ├─systemd-ask-password-console.path
● │ │ ├─systemd-binfmt.service
● │ │ ├─systemd-boot-system-token.service
● │ │ ├─systemd-hwdb-update.service
● │ │ ├─systemd-journal-flush.service
● │ │ ├─systemd-journald.service
● │ │ ├─systemd-machine-id-commit.service
● │ │ ├─systemd-modules-load.service
● │ │ ├─systemd-pstore.service
● │ │ ├─systemd-random-seed.service
● │ │ ├─systemd-sysctl.service
● │ │ ├─systemd-sysusers.service
● │ │ ├─systemd-tmpfiles-setup-dev.service
● │ │ ├─systemd-tmpfiles-setup.service
● │ │ ├─systemd-udev-trigger.service
● │ │ ├─systemd-udevd.service
● │ │ ├─systemd-update-utmp.service
● │ │ ├─cryptsetup.target
● │ │ ├─local-fs.target
● │ │ │ └─systemd-remount-fs.service
● │ │ └─swap.target
● │ └─timers.target
● │ ├─e2scrub_all.timer
● │ ├─fstrim.timer
● │ ├─motd-news.timer
● │ └─systemd-tmpfiles-clean.timer
● ├─getty.target
● │ ├─getty-static.service
● │ ├─[email protected]
● │ └─[email protected]
● ├─nfs-client.target
● │ ├─nfs-blkmap.service
● │ ├─rpc-gssd.service
● │ └─remote-fs-pre.target
● ├─remote-fs.target
● │ └─nfs-client.target
● │ ├─nfs-blkmap.service
● │ ├─rpc-gssd.service
● │ └─remote-fs-pre.target
● └─zfs.target
root@node:~# systemctl list-dependencies app-start-abc.service
app-start-abc.service
● ├─system.slice
● └─sysinit.target
● ├─dev-hugepages.mount
● ├─dev-mqueue.mount
● ├─kmod-static-nodes.service
● ├─proc-sys-fs-binfmt_misc.automount
● ├─sys-fs-fuse-connections.mount
● ├─sys-kernel-config.mount
● ├─sys-kernel-debug.mount
● ├─sys-kernel-tracing.mount
● ├─systemd-ask-password-console.path
● ├─systemd-binfmt.service
● ├─systemd-boot-system-token.service
● ├─systemd-hwdb-update.service
● ├─systemd-journal-flush.service
● ├─systemd-journald.service
● ├─systemd-machine-id-commit.service
● ├─systemd-modules-load.service
● ├─systemd-pstore.service
● ├─systemd-random-seed.service
● ├─systemd-sysctl.service
● ├─systemd-sysusers.service
● ├─systemd-tmpfiles-setup-dev.service
● ├─systemd-tmpfiles-setup.service
● ├─systemd-udev-trigger.service
● ├─systemd-udevd.service
● ├─systemd-update-utmp.service
● ├─cryptsetup.target
● ├─local-fs.target
● │ └─systemd-remount-fs.service
上面命令的输出结果之中，有些依赖是 Target 类型（详见下文），默认不会展开显示。如果要展开 Target，就需要使用–all参数。
root@node:~# systemctl list-dependencies app-start-abc.service --all
app-start-abc.service
● ├─system.slice
● │ └─-.slice
● └─sysinit.target
● ├─dev-hugepages.mount
● │ └─system.slice
● │ └─-.slice
● ├─dev-mqueue.mount
● │ └─system.slice
● │ └─-.slice
● ├─kmod-static-nodes.service
● │ └─system.slice
● │ └─-.slice
● ├─proc-sys-fs-binfmt_misc.automount
● ├─sys-fs-fuse-connections.mount
● │ └─system.slice
● │ └─-.slice
● ├─sys-kernel-config.mount
● │ └─system.slice
● │ └─-.slice
● ├─sys-kernel-debug.mount
● │ └─system.slice
● │ └─-.slice
● ├─sys-kernel-tracing.mount
● │ └─system.slice
● │ └─-.slice
● ├─systemd-ask-password-console.path
● ├─systemd-binfmt.service
● │ └─system.slice
● │ └─-.slice
● ├─systemd-boot-system-token.service
● │ └─system.slice
● │ └─-.slice
● ├─systemd-hwdb-update.service
● │ └─system.slice
● │ └─-.slice
● ├─systemd-journal-flush.service
● │ ├─system.slice
● │ │ └─-.slice
● │ └─systemd-journald.service
● │ ├─system.slice
● │ │ └─-.slice
● │ ├─systemd-journald-audit.socket
● │ │ └─system.slice
● │ │ └─-.slice
● │ ├─systemd-journald-dev-log.socket
● │ │ └─system.slice
● │ │ └─-.slice
● │ └─systemd-journald.socket
● │ └─system.slice
● │ └─-.slice
● ├─systemd-journald.service
● │ ├─system.slice
● │ │ └─-.slice
● │ ├─systemd-journald-audit.socket
● │ │ └─system.slice
● │ │ └─-.slice
● │ ├─systemd-journald-dev-log.socket
● │ │ └─system.slice
● │ │ └─-.slice
● │ └─systemd-journald.socket
● │ └─system.slice
● │ └─-.slice
● ├─systemd-machine-id-commit.service
● │ └─system.slice
● │ └─-.slice
● ├─systemd-modules-load.service
● │ └─system.slice
● │ └─-.slice
● ├─systemd-pstore.service
● │ ├─modprobe@chromeos_pstore.service
● │ │ └─system-modprobe.slice
● │ │ └─system.slice
● │ │ └─-.slice
● │ ├─modprobe@efi_pstore.service
● │ │ └─system-modprobe.slice
● │ │ └─system.slice
● │ │ └─-.slice
● │ ├─modprobe@pstore_blk.service
● │ │ └─system-modprobe.slice
● │ │ └─system.slice
● │ │ └─-.slice
● │ ├─modprobe@pstore_zone.service
● │ │ └─system-modprobe.slice
● │ │ └─system.slice
● │ │ └─-.slice
● │ ├─[email protected]
● │ │ └─system-modprobe.slice
● │ │ └─system.slice
● │ │ └─-.slice
● │ └─system.slice
● │ └─-.slice
● ├─systemd-random-seed.service
● │ └─system.slice
● │ └─-.slice
● ├─systemd-sysctl.service
● │ └─system.slice
● │ └─-.slice
● ├─systemd-sysusers.service
● │ └─system.slice
● │ └─-.slice
● ├─systemd-tmpfiles-setup-dev.service
● │ └─system.slice
● │ └─-.slice
● ├─systemd-tmpfiles-setup.service
● │ └─system.slice
● │ └─-.slice
● ├─systemd-udev-trigger.service
● │ ├─system.slice
● │ │ └─-.slice
● │ └─systemd-udevd.service
● │ ├─system.slice
● │ │ └─-.slice
● │ ├─systemd-udevd-control.socket
● │ │ └─system.slice
● │ │ └─-.slice
● │ └─systemd-udevd-kernel.socket
● │ └─system.slice
● │ └─-.slice
● ├─systemd-udevd.service
● │ ├─system.slice
● │ │ └─-.slice
● │ ├─systemd-udevd-control.socket
● │ │ └─system.slice
● │ │ └─-.slice
● │ └─systemd-udevd-kernel.socket
● │ └─system.slice
● │ └─-.slice
● ├─systemd-update-utmp.service
● │ └─system.slice
● │ └─-.slice
● ├─cryptsetup.target
● ├─local-fs.target
● │ └─systemd-remount-fs.service
● │ ├─system.slice
● │ │ └─-.slice
● │ └─local-fs-pre.target
● └─swap.target
四、Unit 的配置文件
每一个 Unit 都有一个配置文件，告诉 Systemd 怎么启动这个 Unit 。
Systemd
- 默认从目录
/etc/systemd/system/读取配置文件（但里面存放的大部分文件都是符号链接，指向目录/usr/lib/systemd/system/，真正的配置文件存放在那个目录。） - 也可能在/etc/systemd/system目录。
- 找到配置文件以后，使用文本编辑器打开即可。
systemctl enable 命令用于在上面两个目录之间，建立符号链接关系。如果配置文件里面设置了开机启动则相当于激活开机启动。
systemctl enable [email protected]
# 等同于
ln -s '/usr/lib/systemd/system/[email protected]' '/etc/systemd/system/multi-user.target.wants/[email protected]'
systemctl disable命令用于在两个目录之间，撤销符号链接关系，相当于撤销开机启动。
systemctl disable [email protected]
- 配置文件的后缀名，就是该 Unit 的种类，比如 sshd.socket。如果省略，Systemd 默认后缀名为 .service，所以 sshd 会被理解成 sshd.service。
4.1 配置文件层级
root@node:~# ll /etc/systemd/
total 27
drwxr-xr-x 1 root root 4096 Jan 6 14:34 ./
drwxr-xr-x 1 root root 4096 Jan 5 10:38 ../
-rw-r--r-- 1 root root 1029 Feb 20 11:32 journald.conf
-rw-r--r-- 1 root root 1042 Sep 8 2022 logind.conf
lrwxrwxrwx 1 root root 54 Nov 11 16:20 network -> /home/node/SysData/rw_rootfs/etc/systemd/network//
-rw-r--r-- 1 root root 584 Apr 2 2020 networkd.conf
-rw-r--r-- 1 root root 529 Apr 2 2020 pstore.conf
-rw-r--r-- 1 root root 642 Sep 8 2022 resolved.conf
-rw-r--r-- 1 root root 790 Apr 2 2020 sleep.conf
drwxr-xr-x 1 root root 4096 Jan 5 14:38 system/
-rw-r--r-- 1 root root 2180 Jan 31 10:32 system.conf
lrwxrwxrwx 1 root root 60 Nov 11 16:20 timesyncd.conf -> /home/node/SysData/rw_rootfs/etc/systemd/timesyncd.conf
drwxr-xr-x 2 root root 3 Sep 8 2022 user/
-rw-r--r-- 1 root root 1185 Sep 8 2022 user.conf
root@node:~# ll /etc/systemd/system
total 43
drwxr-xr-x 1 root root 4096 Jan 5 14:38 ./
drwxr-xr-x 1 root root 4096 Jan 6 14:34 ../
lrwxrwxrwx 1 root root 9 Nov 11 16:20 apt-daily-upgrade.timer -> /dev/null
lrwxrwxrwx 1 root root 9 Nov 11 16:20 apt-daily.timer -> /dev/null
lrwxrwxrwx 1 root root 44 Nov 24 10:47 dbus-org.freedesktop.resolve1.service -> /lib/systemd/system/systemd-resolved.service
lrwxrwxrwx 1 root root 45 Nov 24 10:47 dbus-org.freedesktop.timesync1.service -> /lib/systemd/system/systemd-timesyncd.service
drwxr-xr-x 2 root root 43 Nov 11 16:20 default.target.wants/
-rw-r--r-- 1 root root 279 Nov 11 16:20 delinux-entry-app.service
-rw-r--r-- 1 root root 241 Nov 11 16:20 delinux-entry-sys.service
-rw-r--r-- 1 root root 1486 Nov 11 16:20 '[email protected]'
-rw-r--r-- 1 root root 492 Nov 11 16:20 '[email protected]'
-rw-r--r-- 1 root root 279 Jan 5 11:13 freyr.service
drwxr-xr-x 2 root root 41 Nov 24 10:47 getty.target.wants/
drwxr-xr-x 2 root root 394 Nov 11 16:20 multi-user.target.wants/
-rw-r--r-- 1 root root 274 Jan 5 11:03 nginx.service
-rw-r--r-- 1 root root 283 Jan 5 11:07 abc.service
-rw-r--r-- 1 root root 274 Jan 5 11:09 redis.service
drwxr-xr-x 2 root root 40 Nov 24 10:51 remote-fs.target.wants/
lrwxrwxrwx 1 root root 9 Nov 11 16:20 '[email protected]' -> /dev/null
lrwxrwxrwx 1 root root 41 Nov 24 10:57 smartd.service -> /lib/systemd/system/smartmontools.service
drwxr-xr-x 2 root root 37 Nov 11 16:20 sockets.target.wants/
lrwxrwxrwx 1 root root 9 Nov 11 16:20 sshd.service -> /dev/null
drwxr-xr-x 2 root root 78 Nov 11 16:20 sysinit.target.wants/
drwxr-xr-x 2 root root 137 Nov 11 16:20 timers.target.wants/
-rw-r--r-- 1 root root 279 Jan 5 14:37 aaa.service
-rw-r--r-- 1 root root 279 Jan 5 14:39 bbb.service
-rw-r--r-- 1 root root 297 Jan 5 11:15 weedfs_master.service
-rw-r--r-- 1 root root 297 Jan 5 11:16 weedfs_volume.service
drwxr-xr-x 2 root root 47 Nov 11 16:20 zfs-import.target.wants/
drwxr-xr-x 2 root root 46 Nov 11 16:20 zfs-mount.service.wants/
drwxr-xr-x 2 root root 46 Nov 11 16:20 zfs-volumes.target.wants/
drwxr-xr-x 2 root root 147 Nov 11 16:20 zfs.target.wants/
root@node:~# cat /etc/systemd/journald.conf
# See journald.conf(5) for details.
[Journal]
Storage=persistent
#Compress=yes
#Seal=yes
#SplitMode=uid
#SyncIntervalSec=5m
RateLimitIntervalSec=0
RateLimitBurst=0
SystemMaxUse=1024M
#SystemKeepFree=
#SystemMaxFileSize=
#SystemMaxFiles=100
#RuntimeMaxUse=
#RuntimeKeepFree=
#RuntimeMaxFileSize=
#RuntimeMaxFiles=100
#MaxRetentionSec=
#MaxFileSec=1month
#ForwardToSyslog=yes
#ForwardToKMsg=no
#ForwardToConsole=no
#ForwardToWall=yes
#TTYPath=/dev/console
#MaxLevelStore=debug
#MaxLevelSyslog=debug
#MaxLevelKMsg=notice
#MaxLevelConsole=info
#MaxLevelWall=emerg
#LineMax=48K
root@node:~# cat /etc/systemd/system.conf
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See systemd-system.conf(5) for details.
[Manager]
#LogLevel=info
#LogTarget=journal-or-kmsg
#LogColor=yes
#LogLocation=no
#DumpCore=yes
#ShowStatus=yes
#CrashChangeVT=no
#CrashShell=no
#CrashReboot=no
#CtrlAltDelBurstAction=reboot-force
#CPUAffinity=1 2
#NUMAPolicy=default
#NUMAMask=
#RuntimeWatchdogSec=0
#RebootWatchdogSec=10min
#ShutdownWatchdogSec=10min
#KExecWatchdogSec=0
#WatchdogDevice=
#CapabilityBoundingSet=
#NoNewPrivileges=no
#SystemCallArchitectures=
#TimerSlackNSec=
#StatusUnitFormat=description
#DefaultTimerAccuracySec=1min
#DefaultStandardOutput=journal
#DefaultStandardError=inherit
#DefaultTimeoutStartSec=90s
DefaultTimeoutStopSec=30s
#DefaultTimeoutAbortSec=
#DefaultRestartSec=100ms
#DefaultStartLimitIntervalSec=10s
#DefaultStartLimitBurst=5
DefaultEnvironment=LANG=C LANGUAGE=C LC_ADDRESS=C.UTF-8 LC_ALL=C.UTF-8 LC_COLLATE=C.UTF-8 LC_CTYPE=C.UTF-8 LC_IDENTIFICATION=C.UTF-8 LC_MEASUREMENT=C.UTF-8 LC_MESSAGES=C.UTF-8 LC_MONETARY=C.UTF-8 LC_NAME=C.UTF-8 LC_NUMERIC=C.UTF-8 LC_PAPER=C.UTF-8 LC_TELEPHONE=C.UTF-8 LC_TIME=C.UTF-8 PATH=/home/node/Applications/docker.app.dpk.mnt/usr/bin:/home/node/Applications/desys.sys.dpk.mnt/bin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
#DefaultCPUAccounting=no
#DefaultIOAccounting=no
#DefaultIPAccounting=no
#DefaultBlockIOAccounting=no
#DefaultMemoryAccounting=yes
#DefaultTasksAccounting=yes
#DefaultTasksMax=
#DefaultLimitCPU=
#DefaultLimitFSIZE=
#DefaultLimitDATA=
#DefaultLimitSTACK=
#DefaultLimitCORE=
#DefaultLimitRSS=
DefaultLimitNOFILE=10240:5242880
#DefaultLimitAS=
#DefaultLimitNPROC=
#DefaultLimitMEMLOCK=
#DefaultLimitLOCKS=
#DefaultLimitSIGPENDING=
#DefaultLimitMSGQUEUE=
#DefaultLimitNICE=
#DefaultLimitRTPRIO=
#DefaultLimitRTTIME=
root@node:~# cat /etc/systemd/user.conf
# You can override the directives in this file by creating files in
# /etc/systemd/user.conf.d/*.conf.
#
# See systemd-user.conf(5) for details
[Manager]
#LogLevel=info
#LogTarget=console
#LogColor=yes
#LogLocation=no
#SystemCallArchitectures=
#TimerSlackNSec=
#StatusUnitFormat=description
#DefaultTimerAccuracySec=1min
#DefaultStandardOutput=inherit
#DefaultStandardError=inherit
#DefaultTimeoutStartSec=90s
#DefaultTimeoutStopSec=90s
#DefaultTimeoutAbortSec=
#DefaultRestartSec=100ms
#DefaultStartLimitIntervalSec=10s
#DefaultStartLimitBurst=5
#DefaultEnvironment=
#DefaultLimitCPU=
#DefaultLimitFSIZE=
#DefaultLimitDATA=
#DefaultLimitSTACK=
#DefaultLimitCORE=
#DefaultLimitRSS=
#DefaultLimitNOFILE=
#DefaultLimitAS=
#DefaultLimitNPROC=
#DefaultLimitMEMLOCK=
#DefaultLimitLOCKS=
#DefaultLimitSIGPENDING=
#DefaultLimitMSGQUEUE=
#DefaultLimitNICE=
#DefaultLimitRTPRIO=
#DefaultLimitRTTIME=
root@node:/etc/systemd# ll
lrwxrwxrwx 1 root root 60 Nov 11 16:20 timesyncd.conf -> /home/node/SysData/rw_rootfs/etc/systemd/timesyncd.conf
root@node:/etc/systemd# cat timesyncd.conf
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See timesyncd.conf(5) for details.
[Time]
NTP=192.168.2.165
#FallbackNTP=ntp.ubuntu.com
#RootDistanceMaxSec=5
#PollIntervalMinSec=32
#PollIntervalMaxSec=2048
root@node:/etc/systemd# ll | grep network
lrwxrwxrwx 1 root root 54 Nov 11 16:20 network -> /home/node/SysData/rw_rootfs/etc/systemd/network//
-rw-r--r-- 1 root root 584 Apr 2 2020 networkd.conf
root@node:/etc/systemd# cat network/eth0.network
[Match]
Name=eth0
[Network]
Address=192.168.100.130/23
[Route]
Gateway=192.168.101.254
root@node:/etc/systemd# cat network/eth1.network
[Match]
Name=eth1
[Network]
Address=192.168.13.188/24
[Route]
Gateway=192.168.13.254
root@node:/etc/systemd# cat networkd.conf/
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See networkd.conf(5) for details
[Network]
#SpeedMeter=no
#SpeedMeterIntervalSec=10sec
[DHCP]
#DUIDType=vendor
#DUIDRawData=
root@node:/etc/systemd/system# ll
total 43
drwxr-xr-x 1 root root 4096 Jan 5 14:38 ./
drwxr-xr-x 1 root root 4096 Jan 6 14:34 ../
lrwxrwxrwx 1 root root 9 Nov 11 16:20 apt-daily-upgrade.timer -> /dev/null
lrwxrwxrwx 1 root root 9 Nov 11 16:20 apt-daily.timer -> /dev/null
lrwxrwxrwx 1 root root 44 Nov 24 10:47 dbus-org.freedesktop..service -> /lib/systemd/system/systemd-resolved.service
lrwxrwxrwx 1 root root 45 Nov 24 10:47 dbus-org.freedesktop.timesync1.service -> /lib/systemd/system/systemd-timesyncd.service
drwxr-xr-x 2 root root 43 Nov 11 16:20 default.target.wants/
-rw-r--r-- 1 root root 279 Nov 11 16:20 delinux-entry-app.service
-rw-r--r-- 1 root root 241 Nov 11 16:20 delinux-entry-sys.service
-rw-r--r-- 1 root root 1486 Nov 11 16:20 '[email protected]'
-rw-r--r-- 1 root root 492 Nov 11 16:20 '[email protected]'
-rw-r--r-- 1 root root 279 Jan 5 11:13 freyr.service
drwxr-xr-x 2 root root 41 Nov 24 10:47 getty.target.wants/
drwxr-xr-x 2 root root 394 Nov 11 16:20 multi-user.target.wants/
-rw-r--r-- 1 root root 274 Jan 5 11:03 nginx.service
-rw-r--r-- 1 root root 283 Jan 5 11:07 abc.service
-rw-r--r-- 1 root root 274 Jan 5 11:09 redis.service
drwxr-xr-x 2 root root 40 Nov 24 10:51 remote-fs.target.wants/
lrwxrwxrwx 1 root root 9 Nov 11 16:20 '[email protected]' -> /dev/null
lrwxrwxrwx 1 root root 41 Nov 24 10:57 smartd.service -> /lib/systemd/system/smartmontools.service
drwxr-xr-x 2 root root 37 Nov 11 16:20 sockets.target.wants/
lrwxrwxrwx 1 root root 9 Nov 11 16:20 sshd.service -> /dev/null
drwxr-xr-x 2 root root 78 Nov 11 16:20 sysinit.target.wants/
drwxr-xr-x 2 root root 137 Nov 11 16:20 timers.target.wants/
-rw-r--r-- 1 root root 279 Jan 5 14:37 aaa.service
-rw-r--r-- 1 root root 279 Jan 5 14:39 bbb.service
-rw-r--r-- 1 root root 297 Jan 5 11:15 weedfs_master.service
-rw-r--r-- 1 root root 297 Jan 5 11:16 weedfs_volume.service
drwxr-xr-x 2 root root 47 Nov 11 16:20 zfs-import.target.wants/
drwxr-xr-x 2 root root 46 Nov 11 16:20 zfs-mount.service.wants/
drwxr-xr-x 2 root root 46 Nov 11 16:20 zfs-volumes.target.wants/
drwxr-xr-x 2 root root 147 Nov 11 16:20 zfs.target.wants/
root@node:/etc/systemd/system# cat sshd.service
root@node:/etc/systemd/system# cat abc.service
[Unit]
Description=This is abc service
[Service]
User=root
LimitNOFILE=65535
ExecStart=/bin/bash -c "cd /home/node/Applications/abc/abc/latest/ && ./run.sh"
SuccessExitStatus=143
TimeoutStopSec=10
Restart=on-failure
RestartSec=3
[Install]
WantedBy=multi-user.target
root@node:/etc/systemd/system# cat redis.service
[Unit]
Description=This is redis service
[Service]
User=root
LimitNOFILE=65535
ExecStart=/bin/bash -c "cd /home/node/Applications/REDIS/latest/ && ./run.sh"
SuccessExitStatus=143
TimeoutStopSec=10
Restart=on-failure
RestartSec=3
[Install]
WantedBy=multi-user.target
root@node:/etc/systemd/system# cat nginx.service
[Unit]
Description=This is nginx service
[Service]
User=root
LimitNOFILE=65535
ExecStart=/bin/bash -c "cd /home/node/Applications/NGINX/latest/ && ./run.sh"
SuccessExitStatus=143
TimeoutStopSec=10
Restart=on-failure
RestartSec=3
[Install]
WantedBy=multi-user.target
root@node:/etc/systemd/system# cat aaa.service
[Unit]
Description=This is aaa service
[Service]
User=root
LimitNOFILE=65535
ExecStart=/bin/bash -c "cd /home/node/Applications/aaa/aaa/latest/ && ./run.sh"
SuccessExitStatus=143
TimeoutStopSec=10
Restart=on-failure
RestartSec=3
[Install]
WantedBy=multi-user.target
root@node:/etc/systemd/system# cat bbb.service
[Unit]
Description=This is bbb service
[Service]
User=root
LimitNOFILE=65535
ExecStart=/bin/bash -c "cd /home/node/Applications/bbb/bbb/latest/ && ./run.sh"
SuccessExitStatus=143
TimeoutStopSec=10
Restart=on-failure
RestartSec=3
[Install]
WantedBy=multi-user.target
root@node:/etc/systemd/system# cat weedfs_master.service
[Unit]
Description=This is weedfs_master service
[Service]
User=root
LimitNOFILE=65535
ExecStart=/bin/bash -c "cd /home/node/Applications/WEEDFS/weedfs/latest && ./run_server.sh"
SuccessExitStatus=143
TimeoutStopSec=10
Restart=on-failure
RestartSec=3
[Install]
WantedBy=multi-user.target
root@node:/etc/systemd/system# cat weedfs_volume.service
[Unit]
Description=This is weedfs_volume service
[Service]
User=root
LimitNOFILE=65535
ExecStart=/bin/bash -c "cd /home/node/Applications/WEEDFS/weedfs/latest && ./run_volume.sh"
SuccessExitStatus=143
TimeoutStopSec=10
Restart=on-failure
RestartSec=3
[Install]
WantedBy=multi-user.target
root@node:/etc/systemd/system/multi-user.target.wants# ll
total 4
drwxr-xr-x 2 root root 394 Nov 11 16:20 ./
drwxr-xr-x 1 root root 4096 Jan 5 14:38 ../
lrwxrwxrwx 1 root root 9 Nov 11 16:20 auditd.service -> /dev/null
lrwxrwxrwx 1 root root 45 Nov 11 16:20 delinux-entry-app.service -> /etc/systemd/system/delinux-entry-app.service
lrwxrwxrwx 1 root root 45 Nov 11 16:20 delinux-entry-sys.service -> /etc/systemd/system/delinux-entry-sys.service
lrwxrwxrwx 1 root root 9 Nov 11 16:20 networkd-dispatcher.service -> /dev/null
lrwxrwxrwx 1 root root 37 Nov 24 10:51 nfs-client.target -> /lib/systemd/system/nfs-client.target
lrwxrwxrwx 1 root root 9 Nov 11 16:20 ondemand.service -> /dev/null
lrwxrwxrwx 1 root root 36 Nov 24 10:47 remote-fs.target -> /lib/systemd/system/remote-fs.target
lrwxrwxrwx 1 root root 9 Nov 11 16:20 rpcbind.service -> /dev/null
lrwxrwxrwx 1 root root 9 Nov 11 16:20 smartmontools.service -> /dev/null
lrwxrwxrwx 1 root root 9 Nov 11 16:20 ssh.service -> /dev/null
lrwxrwxrwx 1 root root 9 Nov 11 16:20 systemd-logind.service -> /dev/null
lrwxrwxrwx 1 root root 44 Nov 11 16:20 systemd-networkd.service -> /lib/systemd/system/systemd-networkd.service
lrwxrwxrwx 1 root root 44 Nov 24 10:47 systemd-resolved.service -> /lib/systemd/system/systemd-resolved.service
lrwxrwxrwx 1 root root 30 Nov 24 18:52 zfs.target -> /lib/systemd/system/zfs.target
root@node:/etc/systemd/system# ll default.target.wants/
total 4
drwxr-xr-x 2 root root 43 Nov 11 16:20 ./
drwxr-xr-x 1 root root 4096 Jan 5 14:38 ../
lrwxrwxrwx 1 root root 9 Nov 11 16:20 e2scrub_reap.service -> /dev/null
root@node:/etc/systemd/system# ll getty.target.wants/
total 4
drwxr-xr-x 2 root root 41 Nov 24 10:47 ./
drwxr-xr-x 1 root root 4096 Jan 5 14:38 ../
lrwxrwxrwx 1 root root 34 Nov 24 10:47 '[email protected]' -> '/lib/systemd/system/[email protected]'
root@node:/etc/systemd/system# ll sysinit.target.wants/
total 4
drwxr-xr-x 2 root root 78 Nov 11 16:20 ./
drwxr-xr-x 1 root root 4096 Jan 5 14:38 ../
lrwxrwxrwx 1 root root 42 Nov 24 10:47 systemd-pstore.service -> /lib/systemd/system/systemd-pstore.service
lrwxrwxrwx 1 root root 9 Nov 11 16:20 systemd-timesyncd.service -> /dev/null
root@node:/etc/systemd/system# ll sockets.target.wants/
total 4
drwxr-xr-x 2 root root 37 Nov 11 16:20 ./
drwxr-xr-x 1 root root 4096 Jan 5 14:38 ../
lrwxrwxrwx 1 root root 9 Nov 11 16:20 rpcbind.socket -> /dev/null
root@node:/etc/systemd/system# ll timers.target.wants/
total 4
drwxr-xr-x 2 root root 137 Nov 11 16:20 ./
drwxr-xr-x 1 root root 4096 Jan 5 14:38 ../
lrwxrwxrwx 1 root root 9 Nov 11 16:20 apt-daily-upgrade.timer -> /dev/null
lrwxrwxrwx 1 root root 9 Nov 11 16:20 apt-daily.timer -> /dev/null
lrwxrwxrwx 1 root root 37 Feb 22 2022 e2scrub_all.timer -> /lib/systemd/system/e2scrub_all.timer
lrwxrwxrwx 1 root root 32 Feb 22 2022 fstrim.timer -> /lib/systemd/system/fstrim.timer
lrwxrwxrwx 1 root root 35 Feb 22 2022 motd-news.timer -> /lib/systemd/system/motd-news.timer
root@node:/usr/lib/systemd# ll
total 8326
drwxr-xr-x 16 root root 1535 Nov 11 16:20 ./
drwxr-xr-x 1 root root 4096 May 31 2022 ../
drwxr-xr-x 3 root root 26 Nov 24 10:47 boot/
drwxr-xr-x 2 root root 339 Nov 24 10:47 catalog/
-rw-r--r-- 1 root root 2446488 Sep 8 2022 libsystemd-shared-245.so
drwxr-xr-x 2 root root 266 Nov 24 10:55 network/
drwxr-xr-x 2 root root 47 Nov 24 10:47 ntp-units.d/
-rw-r--r-- 1 root root 701 Sep 8 2022 resolv.conf
drwxr-xr-x 2 root root 39 Nov 24 10:51 scripts/
-rwxr-xr-x 1 root root 1246 Sep 8 2022 set-cpufreq*
drwxr-xr-x 18 root root 6894 Nov 11 16:20 system/
drwxr-xr-x 2 root root 452 Nov 24 18:51 system-generators/
drwxr-xr-x 2 root root 61 Nov 24 18:51 system-preset/
drwxr-xr-x 2 root root 3 Sep 8 2022 system-shutdown/
drwxr-xr-x 2 root root 3 Sep 8 2022 system-sleep/
-rwxr-xr-x 1 root root 1551488 Sep 8 2022 systemd*
-rwxr-xr-x 1 root root 10240 Sep 8 2022 systemd-ac-power*
-rwxr-xr-x 1 root root 22520 Sep 8 2022 systemd-backlight*
-rwxr-xr-x 1 root root 14408 Sep 8 2022 systemd-binfmt*
-rwxr-xr-x 1 root root 22632 Sep 8 2022 systemd-bless-boot*
-rwxr-xr-x 1 root root 10240 Sep 8 2022 systemd-boot-check-no-failures*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-cgroups-agent*
-rwxr-xr-x 1 root root 31024 Sep 8 2022 systemd-cryptsetup*
-rwxr-xr-x 1 root root 14448 Sep 8 2022 systemd-dissect*
-rwxr-xr-x 1 root root 22456 Sep 8 2022 systemd-fsck*
-rwxr-xr-x 1 root root 22528 Sep 8 2022 systemd-fsckd*
-rwxr-xr-x 1 root root 18432 Sep 8 2022 systemd-growfs*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-hibernate-resume*
-rwxr-xr-x 1 root root 26624 Sep 8 2022 systemd-hostnamed*
-rwxr-xr-x 1 root root 14336 Sep 8 2022 systemd-initctl*
-rwxr-xr-x 1 root root 149552 Sep 8 2022 systemd-journald*
-rwxr-xr-x 1 root root 38912 Sep 8 2022 systemd-localed*
-rwxr-xr-x 1 root root 252112 Sep 8 2022 systemd-logind*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-makefs*
-rwxr-xr-x 1 root root 14440 Sep 8 2022 systemd-modules-load*
-rwxr-xr-x 1 root root 30720 Sep 8 2022 systemd-network-generator*
-rwxr-xr-x 1 root root 2218920 Sep 8 2022 systemd-networkd*
-rwxr-xr-x 1 root root 26808 Sep 8 2022 systemd-networkd-wait-online*
-rwxr-xr-x 1 root root 18456 Sep 8 2022 systemd-pstore*
-rwxr-xr-x 1 root root 10240 Sep 8 2022 systemd-quotacheck*
-rwxr-xr-x 1 root root 18352 Sep 8 2022 systemd-random-seed*
-rwxr-xr-x 1 root root 18456 Sep 8 2022 systemd-remount-fs*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-reply-password*
-rwxr-xr-x 1 root root 399472 Sep 8 2022 systemd-resolved*
-rwxr-xr-x 1 root root 18432 Sep 8 2022 systemd-rfkill*
-rwxr-xr-x 1 root root 47168 Sep 8 2022 systemd-shutdown*
-rwxr-xr-x 1 root root 18576 Sep 8 2022 systemd-sleep*
-rwxr-xr-x 1 root root 22528 Sep 8 2022 systemd-socket-proxyd*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-sulogin-shell*
-rwxr-xr-x 1 root root 18584 Sep 8 2022 systemd-sysctl*
-rwxr-xr-x 1 root root 1360 Jul 20 2022 systemd-sysv-install*
-rwxr-xr-x 1 root root 14256 Sep 8 2022 systemd-time-wait-sync*
-rwxr-xr-x 1 root root 38984 Sep 8 2022 systemd-timedated*
-rwxr-xr-x 1 root root 47104 Sep 8 2022 systemd-timesyncd*
-rwxr-xr-x 1 root root 740368 Sep 8 2022 systemd-udevd*
-rwxr-xr-x 1 root root 14360 Sep 8 2022 systemd-update-utmp*
-rwxr-xr-x 1 root root 14280 Sep 8 2022 systemd-user-runtime-dir*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-user-sessions*
-rwxr-xr-x 1 root root 14392 Sep 8 2022 systemd-veritysetup*
-rwxr-xr-x 1 root root 14256 Sep 8 2022 systemd-volatile-root*
drwxr-xr-x 3 root root 527 Nov 24 10:52 user/
drwxr-xr-x 2 root root 57 Nov 24 10:47 user-environment-generators/
drwxr-xr-x 2 root root 3 Sep 8 2022 user-generators/
drwxr-xr-x 2 root root 40 Nov 24 10:47 user-preset/
root@node:/usr/lib/systemd/system# ll
total 174
drwxr-xr-x 18 root root 6894 Nov 11 16:20 ./
drwxr-xr-x 16 root root 1535 Nov 11 16:20 ../
-rw-r--r-- 1 root root 389 Jun 15 2021 apt-daily-upgrade.service
-rw-r--r-- 1 root root 184 Jun 15 2021 apt-daily-upgrade.timer
-rw-r--r-- 1 root root 326 Jun 15 2021 apt-daily.service
-rw-r--r-- 1 root root 156 Jun 15 2021 apt-daily.timer
-rw-r--r-- 1 root root 652 May 25 2021 auth-rpcgss-module.service
lrwxrwxrwx 1 root root 14 Sep 8 2022 '[email protected]' -> '[email protected]'
-rw-r--r-- 1 root root 919 Apr 2 2020 basic.target
-rw-r--r-- 1 root root 441 Apr 2 2020 '[email protected]'
-rw-r--r-- 1 root root 419 Apr 2 2020 bluetooth.target
-rw-r--r-- 1 root root 455 Apr 2 2020 boot-complete.target
-rw-r--r-- 1 root root 1082 Sep 8 2022 console-getty.service
-rw-r--r-- 1 root root 1263 Sep 8 2022 '[email protected]'
lrwxrwxrwx 1 root root 9 Sep 8 2022 cryptdisks-early.service -> /dev/null
lrwxrwxrwx 1 root root 9 Sep 8 2022 cryptdisks.service -> /dev/null
-rw-r--r-- 1 root root 465 Apr 2 2020 cryptsetup-pre.target
-rw-r--r-- 1 root root 412 Apr 2 2020 cryptsetup.target
lrwxrwxrwx 1 root root 13 Sep 8 2022 ctrl-alt-del.target -> reboot.target
lrwxrwxrwx 1 root root 25 Sep 8 2022 dbus-org.freedesktop.hostname1.service -> systemd-hostnamed.service
lrwxrwxrwx 1 root root 23 Sep 8 2022 dbus-org.freedesktop.locale1.service -> systemd-localed.service
lrwxrwxrwx 1 root root 22 Sep 8 2022 dbus-org.freedesktop.login1.service -> systemd-logind.service
lrwxrwxrwx 1 root root 25 Sep 8 2022 dbus-org.freedesktop.timedate1.service -> systemd-timedated.service
-rw-r--r-- 1 root root 505 Oct 25 21:09 dbus.service
-rw-r--r-- 1 root root 106 Oct 25 21:09 dbus.socket
-rw-r--r-- 1 root root 1057 Sep 8 2022 debug-shell.service
lrwxrwxrwx 1 root root 16 Sep 8 2022 default.target -> graphical.target
-rw-r--r-- 1 root root 750 Apr 2 2020 dev-hugepages.mount
-rw-r--r-- 1 root root 693 Apr 2 2020 dev-mqueue.mount
-rw-r--r-- 1 root root 438 Feb 14 2020 '[email protected]'
-rw-r--r-- 1 root root 297 Feb 14 2020 e2scrub_all.service
-rw-r--r-- 1 root root 251 Feb 14 2020 e2scrub_all.timer
-rw-r--r-- 1 root root 246 Feb 14 2020 '[email protected]'
-rw-r--r-- 1 root root 550 Feb 14 2020 e2scrub_reap.service
-rw-r--r-- 1 root root 797 Sep 8 2022 emergency.service
-rw-r--r-- 1 root root 471 Apr 2 2020 emergency.target
-rw-r--r-- 1 root root 541 Apr 2 2020 exit.target
-rw-r--r-- 1 root root 480 Apr 2 2020 final.target
-rw-r--r-- 1 root root 466 Feb 7 2022 fstrim.service
-rw-r--r-- 1 root root 205 Feb 7 2022 fstrim.timer
-rw-r--r-- 1 root root 506 Apr 2 2020 getty-pre.target
-rw-r--r-- 1 root root 342 Aug 8 2022 getty-static.service
-rw-r--r-- 1 root root 500 Apr 2 2020 getty.target
drwxr-xr-x 2 root root 43 Nov 24 10:47 getty.target.wants/
-rw-r--r-- 1 root root 1975 Sep 8 2022 '[email protected]'
-rw-r--r-- 1 root root 598 Apr 2 2020 graphical.target
drwxr-xr-x 2 root root 59 Nov 24 10:47 graphical.target.wants/
-rw-r--r-- 1 root root 527 Apr 2 2020 halt.target
-rw-r--r-- 1 root root 509 Apr 2 2020 hibernate.target
lrwxrwxrwx 1 root root 9 Sep 8 2022 hwclock.service -> /dev/null
-rw-r--r-- 1 root root 530 Apr 2 2020 hybrid-sleep.target
-rw-r--r-- 1 root root 665 Apr 2 2020 initrd-cleanup.service
-rw-r--r-- 1 root root 528 Apr 2 2020 initrd-fs.target
-rw-r--r-- 1 root root 815 Apr 2 2020 initrd-parse-etc.service
-rw-r--r-- 1 root root 496 Apr 2 2020 initrd-root-device.target
-rw-r--r-- 1 root root 501 Apr 2 2020 initrd-root-fs.target
-rw-r--r-- 1 root root 584 Apr 2 2020 initrd-switch-root.service
-rw-r--r-- 1 root root 777 Apr 2 2020 initrd-switch-root.target
-rw-r--r-- 1 root root 813 Apr 2 2020 initrd-udevadm-cleanup-db.service
-rw-r--r-- 1 root root 698 Apr 2 2020 initrd.target
-rw-r--r-- 1 root root 541 Apr 2 2020 kexec.target
-rw-r--r-- 1 root root 716 Sep 8 2022 kmod-static-nodes.service
lrwxrwxrwx 1 root root 28 Sep 8 2022 kmod.service -> systemd-modules-load.service
-rw-r--r-- 1 root root 435 Apr 2 2020 local-fs-pre.target
-rw-r--r-- 1 root root 482 Apr 2 2020 local-fs.target
drwxr-xr-x 2 root root 3 Sep 8 2022 local-fs.target.wants/
-rw-r--r-- 1 root root 445 Apr 2 2020 machine.slice
-rw-r--r-- 1 root root 601 Sep 8 2022 '[email protected]'
-rw-r--r-- 1 root root 173 Jun 16 2020 motd-news.service
-rw-r--r-- 1 root root 161 Jun 16 2020 motd-news.timer
-rw-r--r-- 1 root root 532 Apr 2 2020 multi-user.target
drwxr-xr-x 2 root root 204 Nov 24 10:56 multi-user.target.wants/
-rw-r--r-- 1 root root 505 Apr 2 2020 network-online.target
-rw-r--r-- 1 root root 502 Apr 2 2020 network-pre.target
-rw-r--r-- 1 root root 521 Apr 2 2020 network.target
-rw-r--r-- 1 root root 272 May 25 2021 nfs-client.target
lrwxrwxrwx 1 root root 9 May 25 2021 nfs-common.service -> /dev/null
-rw-r--r-- 1 root root 375 May 25 2021 nfs-config.service
-rw-r--r-- 1 root root 336 May 25 2021 nfs-idmapd.service
-rw-r--r-- 1 root root 567 Aug 4 2016 nfs-utils.service
-rw-r--r-- 1 root root 554 Apr 2 2020 nss-lookup.target
-rw-r--r-- 1 root root 513 Apr 2 2020 nss-user-lookup.target
-rw-r--r-- 1 root root 362 Aug 8 2022 ondemand.service
-rw-r--r-- 1 root root 394 Apr 2 2020 paths.target
lrwxrwxrwx 1 root root 15 Sep 18 2019 portmap.service -> rpcbind.service
-rw-r--r-- 1 root root 592 Apr 2 2020 poweroff.target
-rw-r--r-- 1 root root 417 Apr 2 2020 printer.target
-rw-r--r-- 1 root root 98 Aug 4 2016 proc-fs-nfsd.mount
-rw-r--r-- 1 root root 745 Apr 2 2020 proc-sys-fs-binfmt_misc.automount
-rw-r--r-- 1 root root 718 Apr 2 2020 proc-sys-fs-binfmt_misc.mount
lrwxrwxrwx 1 root root 22 Sep 8 2022 procps.service -> systemd-sysctl.service
-rw-r--r-- 1 root root 609 Sep 8 2022 quotaon.service
-rw-r--r-- 1 root root 716 Sep 8 2022 rc-local.service
drwxr-xr-x 2 root root 34 Nov 24 10:47 rc-local.service.d/
lrwxrwxrwx 1 root root 9 Sep 8 2022 rc.service -> /dev/null
lrwxrwxrwx 1 root root 9 Sep 8 2022 rcS.service -> /dev/null
-rw-r--r-- 1 root root 583 Apr 2 2020 reboot.target
-rw-r--r-- 1 root root 549 Apr 2 2020 remote-cryptsetup.target
-rw-r--r-- 1 root root 436 Apr 2 2020 remote-fs-pre.target
-rw-r--r-- 1 root root 522 Apr 2 2020 remote-fs.target
-rw-r--r-- 1 root root 184 Mar 30 2022 rescue-ssh.target
-rw-r--r-- 1 root root 788 Sep 8 2022 rescue.service
-rw-r--r-- 1 root root 492 Apr 2 2020 rescue.target
drwxr-xr-x 2 root root 59 Nov 24 10:47 rescue.target.wants/
-rw-r--r-- 1 root root 391 May 25 2021 rpc-gssd.service
-rw-r--r-- 1 root root 497 May 25 2021 rpc-statd-notify.service
-rw-r--r-- 1 root root 489 May 25 2021 rpc-statd.service
-rw-r--r-- 1 root root 402 May 25 2021 rpc-svcgssd.service
-rw-r--r-- 1 root root 626 Sep 18 2019 rpcbind.service
-rw-r--r-- 1 root root 325 Sep 18 2019 rpcbind.socket
-rw-r--r-- 1 root root 540 Apr 2 2020 rpcbind.target
-rw-r--r-- 1 root root 146 May 25 2021 run-rpc_pipefs.mount
lrwxrwxrwx 1 root root 15 Sep 8 2022 runlevel0.target -> poweroff.target
lrwxrwxrwx 1 root root 13 Sep 8 2022 runlevel1.target -> rescue.target
drwxr-xr-x 2 root root 3 Sep 8 2022 runlevel1.target.wants/
lrwxrwxrwx 1 root root 17 Sep 8 2022 runlevel2.target -> multi-user.target
drwxr-xr-x 2 root root 3 Sep 8 2022 runlevel2.target.wants/
lrwxrwxrwx 1 root root 17 Sep 8 2022 runlevel3.target -> multi-user.target
drwxr-xr-x 2 root root 3 Sep 8 2022 runlevel3.target.wants/
lrwxrwxrwx 1 root root 17 Sep 8 2022 runlevel4.target -> multi-user.target
drwxr-xr-x 2 root root 3 Sep 8 2022 runlevel4.target.wants/
lrwxrwxrwx 1 root root 16 Sep 8 2022 runlevel5.target -> graphical.target
drwxr-xr-x 2 root root 3 Sep 8 2022 runlevel5.target.wants/
lrwxrwxrwx 1 root root 13 Sep 8 2022 runlevel6.target -> reboot.target
-rw-r--r-- 1 root root 1486 Sep 8 2022 '[email protected]'
-rw-r--r-- 1 root root 442 Apr 2 2020 shutdown.target
-rw-r--r-- 1 root root 402 Apr 2 2020 sigpwr.target
-rw-r--r-- 1 root root 460 Apr 2 2020 sleep.target
-rw-r--r-- 1 root root 449 Apr 2 2020 slices.target
-rw-r--r-- 1 root root 420 Apr 2 2020 smartcard.target
-rw-r--r-- 1 root root 348 Mar 21 2020 smartmontools.service
-rw-r--r-- 1 root root 396 Apr 2 2020 sockets.target
drwxr-xr-x 2 root root 242 Nov 24 10:56 sockets.target.wants/
-rw-r--r-- 1 root root 420 Apr 2 2020 sound.target
-rw-r--r-- 1 root root 538 Mar 30 2022 ssh.service
-rw-r--r-- 1 root root 216 May 9 2020 ssh.socket
-rw-r--r-- 1 root root 318 Mar 30 2022 '[email protected]'
lrwxrwxrwx 1 root root 9 Jan 19 2021 sudo.service -> /dev/null
-rw-r--r-- 1 root root 577 Apr 2 2020 suspend-then-hibernate.target
-rw-r--r-- 1 root root 503 Apr 2 2020 suspend.target
-rw-r--r-- 1 root root 393 Apr 2 2020 swap.target
-rw-r--r-- 1 root root 823 Apr 2 2020 sys-fs-fuse-connections.mount
-rw-r--r-- 1 root root 830 Sep 8 2022 sys-kernel-config.mount
-rw-r--r-- 1 root root 738 Apr 2 2020 sys-kernel-debug.mount
-rw-r--r-- 1 root root 764 Apr 2 2020 sys-kernel-tracing.mount
-rw-r--r-- 1 root root 558 Apr 2 2020 sysinit.target
drwxr-xr-x 2 root root 865 Nov 24 10:55 sysinit.target.wants/
-rw-r--r-- 1 root root 1407 Apr 2 2020 syslog.socket
-rw-r--r-- 1 root root 434 Apr 2 2020 'system-systemd\x2dcryptsetup.slice'
-rw-r--r-- 1 root root 1415 Apr 2 2020 system-update-cleanup.service
-rw-r--r-- 1 root root 543 Apr 2 2020 system-update-pre.target
-rw-r--r-- 1 root root 617 Apr 2 2020 system-update.target
-rw-r--r-- 1 root root 722 Apr 2 2020 systemd-ask-password-console.path
-rw-r--r-- 1 root root 737 Apr 2 2020 systemd-ask-password-console.service
-rw-r--r-- 1 root root 650 Apr 2 2020 systemd-ask-password-wall.path
-rw-r--r-- 1 root root 742 Apr 2 2020 systemd-ask-password-wall.service
-rw-r--r-- 1 root root 719 Sep 8 2022 '[email protected]'
-rw-r--r-- 1 root root 1175 Sep 8 2022 systemd-binfmt.service
-rw-r--r-- 1 root root 678 Sep 8 2022 systemd-bless-boot.service
-rw-r--r-- 1 root root 718 Sep 8 2022 systemd-boot-check-no-failures.service
-rw-r--r-- 1 root root 1371 Apr 2 2020 systemd-boot-system-token.service
-rw-r--r-- 1 root root 556 Apr 2 2020 systemd-exit.service
-rw-r--r-- 1 root root 740 Sep 8 2022 systemd-fsck-root.service
-rw-r--r-- 1 root root 741 Sep 8 2022 '[email protected]'
-rw-r--r-- 1 root root 551 Sep 8 2022 systemd-fsckd.service
-rw-r--r-- 1 root root 540 Sep 8 2022 systemd-fsckd.socket
-rw-r--r-- 1 root root 579 Apr 2 2020 systemd-halt.service
-rw-r--r-- 1 root root 671 Sep 8 2022 '[email protected]'
-rw-r--r-- 1 root root 541 Sep 8 2022 systemd-hibernate.service
-rw-r--r-- 1 root root 1157 Nov 11 16:20 systemd-hostnamed.service
-rw-r--r-- 1 root root 813 Sep 8 2022 systemd-hwdb-update.service
-rw-r--r-- 1 root root 559 Sep 8 2022 systemd-hybrid-sleep.service
-rw-r--r-- 1 root root 566 Sep 8 2022 systemd-initctl.service
-rw-r--r-- 1 root root 546 Apr 2 2020 systemd-initctl.socket
-rw-r--r-- 1 root root 773 Apr 2 2020 systemd-journal-flush.service
-rw-r--r-- 1 root root 686 Sep 8 2022 systemd-journald-audit.socket
-rw-r--r-- 1 root root 1130 Apr 2 2020 systemd-journald-dev-log.socket
-rw-r--r-- 1 root root 597 Apr 2 2020 '[email protected]'
-rw-r--r-- 1 root root 1558 Sep 8 2022 systemd-journald.service
-rw-r--r-- 1 root root 882 Apr 2 2020 systemd-journald.socket
-rw-r--r-- 1 root root 1466 Sep 8 2022 '[email protected]'
-rw-r--r-- 1 root root 738 Apr 2 2020 '[email protected]'
-rw-r--r-- 1 root root 592 Apr 2 2020 systemd-kexec.service
-rw-r--r-- 1 root root 1147 Sep 8 2022 systemd-localed.service
-rw-r--r-- 1 root root 2087 Sep 8 2022 systemd-logind.service
-rw-r--r-- 1 root root 728 Apr 2 2020 systemd-machine-id-commit.service
-rw-r--r-- 1 root root 1042 Sep 8 2022 systemd-modules-load.service
-rw-r--r-- 1 root root 635 Sep 8 2022 systemd-network-generator.service
-rw-r--r-- 1 root root 753 Nov 11 16:20 systemd-networkd-wait-online.service
-rw-r--r-- 1 root root 1999 Nov 11 16:20 systemd-networkd.service
-rw-r--r-- 1 root root 633 Apr 2 2020 systemd-networkd.socket
-rw-r--r-- 1 root root 556 Apr 2 2020 systemd-poweroff.service
-rw-r--r-- 1 root root 1033 Sep 8 2022 systemd-pstore.service
-rw-r--r-- 1 root root 655 Sep 8 2022 systemd-quotacheck.service
-rw-r--r-- 1 root root 1059 Sep 8 2022 systemd-random-seed.service
-rw-r--r-- 1 root root 551 Apr 2 2020 systemd-reboot.service
-rw-r--r-- 1 root root 767 Sep 8 2022 systemd-remount-fs.service
-rw-r--r-- 1 root root 1731 Sep 8 2022 systemd-resolved.service
-rw-r--r-- 1 root root 717 Sep 8 2022 systemd-rfkill.service
-rw-r--r-- 1 root root 726 Apr 2 2020 systemd-rfkill.socket
-rw-r--r-- 1 root root 596 Sep 8 2022 systemd-suspend-then-hibernate.service
-rw-r--r-- 1 root root 537 Sep 8 2022 systemd-suspend.service
-rw-r--r-- 1 root root 693 Sep 8 2022 systemd-sysctl.service
-rw-r--r-- 1 root root 695 Apr 2 2020 systemd-sysusers.service
-rw-r--r-- 1 root root 1196 Sep 8 2022 systemd-time-wait-sync.service
-rw-r--r-- 1 root root 1140 Nov 11 16:20 systemd-timedated.service
-rw-r--r-- 1 root root 1483 Nov 11 16:20 systemd-timesyncd.service
-rw-r--r-- 1 root root 658 Apr 2 2020 systemd-tmpfiles-clean.service
-rw-r--r-- 1 root root 490 Apr 2 2020 systemd-tmpfiles-clean.timer
-rw-r--r-- 1 root root 739 Apr 2 2020 systemd-tmpfiles-setup-dev.service
-rw-r--r-- 1 root root 779 Apr 2 2020 systemd-tmpfiles-setup.service
-rw-r--r-- 1 root root 852 Apr 2 2020 systemd-udev-settle.service
-rw-r--r-- 1 root root 753 Apr 2 2020 systemd-udev-trigger.service
-rw-r--r-- 1 root root 635 Apr 2 2020 systemd-udevd-control.socket
-rw-r--r-- 1 root root 610 Apr 2 2020 systemd-udevd-kernel.socket
-rw-r--r-- 1 root root 1151 Sep 8 2022 systemd-udevd.service
-rw-r--r-- 1 root root 797 Sep 8 2022 systemd-update-utmp-runlevel.service
-rw-r--r-- 1 root root 794 Sep 8 2022 systemd-update-utmp.service
-rw-r--r-- 1 root root 628 Sep 8 2022 systemd-user-sessions.service
-rw-r--r-- 1 root root 690 Sep 8 2022 systemd-volatile-root.service
-rw-r--r-- 1 root root 426 Apr 2 2020 time-set.target
-rw-r--r-- 1 root root 479 Apr 2 2020 time-sync.target
-rw-r--r-- 1 root root 445 Apr 2 2020 timers.target
drwxr-xr-x 2 root root 51 Nov 24 10:47 timers.target.wants/
lrwxrwxrwx 1 root root 21 Sep 8 2022 udev.service -> systemd-udevd.service
-rw-r--r-- 1 root root 457 Apr 2 2020 umount.target
drwxr-xr-x 2 root root 39 Nov 24 10:47 user-.slice.d/
-rw-r--r-- 1 root root 688 Sep 8 2022 '[email protected]'
-rw-r--r-- 1 root root 432 Apr 2 2020 user.slice
-rw-r--r-- 1 root root 748 Sep 8 2022 '[email protected]'
drwxr-xr-x 2 root root 35 Nov 24 10:47 '[email protected]'/
lrwxrwxrwx 1 root root 9 Sep 8 2022 x11-common.service -> /dev/null
-rw-r--r-- 1 root root 496 Oct 12 2021 zfs-import-cache.service
-rw-r--r-- 1 root root 466 Oct 12 2021 zfs-import-scan.service
lrwxrwxrwx 1 root root 9 Oct 12 2021 zfs-import.service -> /dev/null
-rw-r--r-- 1 root root 101 Oct 12 2021 zfs-import.target
-rw-r--r-- 1 root root 356 Oct 12 2021 zfs-load-module.service
-rw-r--r-- 1 root root 373 Oct 12 2021 zfs-mount.service
-rw-r--r-- 1 root root 435 Oct 12 2021 zfs-share.service
-rw-r--r-- 1 root root 250 Oct 12 2021 zfs-volume-wait.service
-rw-r--r-- 1 root root 135 Oct 12 2021 zfs-volumes.target
-rw-r--r-- 1 root root 76 Oct 12 2021 zfs.target
4.2 配置文件的状态
这个列表显示每个配置文件的状态，一共有四种。
- enabled：已建立启动链接
- disabled：没建立启动链接
- static：该配置文件没有[Install]部分（无法执行），只能作为其他配置文件的依赖
- masked：该配置文件被禁止建立启动链接
- transient: 临时的，可限制此服务运行时所用资源
root@node:~/PKG# systemctl list-unit-files
UNIT FILE STATE VENDOR PRESET
proc-sys-fs-binfmt_misc.automount static enabled
dev-hugepages.mount static enabled
dev-mqueue.mount static enabled
proc-fs-nfsd.mount static enabled
proc-sys-fs-binfmt_misc.mount disabled enabled
root@node:~/PKG# systemctl list-unit-files --type=service
一旦修改配置文件，就要让 SystemD 重新加载配置文件，然后重新启动，否则修改不会生效。
systemctl daemon-reload
systemctl restart httpd.service
4.3 配置文件的格式
配置文件就是普通的文本文件，可用文本编辑器打开。systemctl cat 命令可查看配置文件内容。注意键值对的等号两侧不能有空格。
root@node:~# systemctl cat app-start-abc.service
# /run/systemd/transient/app-start-abc.service
# This is a transient unit file, created programmatically via the systemd API. Do not e>
[Unit]
Description=run abc
[Service]
KillMode=control-group
Restart=always
RestartSec=3s
RestartPreventExitStatus=255
LimitNOFILE=65535
LimitNOFILE=65535
ExecStart=
ExecStart="/home/node/Applications/abc.app.dpk.mnt/run.sh"
# /run/systemd/transient/app-start-abc.service.d/50-CPUShares.conf
# This is a drop-in unit file extension, created via "systemctl set-property"
# or an equivalent operation. Do not edit.
[Service]
CPUShares=500
4.4 配置文件的区块
Unit 配置文件的完整字段清单，请参考官方文档。
4.4.1 [Unit]
[Unit] 区块通常是配置文件的第一个区块，用来定义 Unit 的元数据，以及配置与其他 Unit 的关系。它的主要字段如下：
- Description：简短描述
- Documentation：文档地址
- Requires：当前 Unit 依赖的其他 Unit，如果它们没有运行，当前 Unit 会启动失败
- Wants：与当前 Unit 配合的其他 Unit，如果它们没有运行，当前 Unit 不会启动失败
- BindsTo：与 Requires 类似，它指定的 Unit 如果退出，会导致当前 Unit 停止运行
- Before：此 Unit 必须在指定的 Unit 之前启动
- After：此 Unit 必须在指定的 Unit 之后启动
- Conflicts：这里指定的 Unit 不能与当前 Unit 同时运行
- Condition…：当前 Unit 运行必须满足的条件，否则不会运行
- Assert…：当前 Unit 运行必须满足的条件，否则会报启动失败
4.4.2 [Install]
[Install] 通常是配置文件的最后一个区块，用来定义如何启动，以及是否开机启动。它的主要字段如下。
- WantedBy：它的值是一个或多个 Target，当前 Unit 激活时（enable）符号链接会放入 /etc/systemd/system 目录下面以 Target 名 + .wants后缀构成的子目录中
- RequiredBy：它的值是一个或多个 Target，当前 Unit 激活时，ll符号链接会放入 /etc/systemd/system 目录下面以 Target 名 + .required后缀构成的子目录中
- Alias：当前 Unit 可用于启动的别名
- Also：当前 Unit 激活（enable）时，会被同时激活的其他 Unit
root@node:/etc/systemd/system# ll | grep wants
drwxr-xr-x 2 root root 43 Nov 11 16:20 default.target.wants/
drwxr-xr-x 2 root root 41 Nov 24 10:47 getty.target.wants/
drwxr-xr-x 2 root root 394 Nov 11 16:20 multi-user.target.wants/
drwxr-xr-x 2 root root 40 Nov 24 10:51 remote-fs.target.wants/
drwxr-xr-x 2 root root 37 Nov 11 16:20 sockets.target.wants/
drwxr-xr-x 2 root root 78 Nov 11 16:20 sysinit.target.wants/
drwxr-xr-x 2 root root 137 Nov 11 16:20 timers.target.wants/
drwxr-xr-x 2 root root 47 Nov 11 16:20 zfs-import.target.wants/
drwxr-xr-x 2 root root 46 Nov 11 16:20 zfs-mount.service.wants/
drwxr-xr-x 2 root root 46 Nov 11 16:20 zfs-volumes.target.wants/
drwxr-xr-x 2 root root 147 Nov 11 16:20 zfs.target.wants/
root@node:/etc/systemd/system# ll sockets.target.wants/
total 4
drwxr-xr-x 2 root root 37 Nov 11 16:20 ./
drwxr-xr-x 1 root root 4096 Jan 5 14:38 ../
lrwxrwxrwx 1 root root 9 Nov 11 16:20 rpcbind.socket -> /dev/null
4.4.3 [Service]
[Service] 区块用来 Service 的配置，只有 Service 类型的 Unit 才有这个区块。它的主要字段如下：
- Type：定义启动时的进程行为。它有以下几种值。
- Type=simple：默认值，执行ExecStart指定的命令，启动主进程
- Type=forking：以 fork 方式从父进程创建子进程，创建后父进程会立即退出
- Type=oneshot：一次性进程，Systemd 会等当前服务退出，再继续往下执行
- Type=dbus：当前服务通过 D-Bus 启动
- Type=notify：当前服务启动完毕，会通知 Systemd，再继续往下执行
- Type=idle：若有其他任务执行完毕，当前服务才会运行
- ExecStart：启动当前服务的命令
- ExecStartPre：启动当前服务之前执行的命令
- ExecStartPost：启动当前服务之后执行的命令
- ExecReload：重启当前服务时执行的命令
- ExecStop：停止当前服务时执行的命令
- ExecStopPost：停止当其服务之后执行的命令
- RestartSec：自动重启当前服务间隔的秒数
- Restart：定义何种情况 Systemd 会自动重启当前服务，可能的值包括always（总是重启）、on-success、on-failure、on-abnormal、on-abort、on-watchdog
- TimeoutSec：定义 Systemd 停止当前服务之前等待的秒数
- Environment：指定环境变量
五、Target 是 Unit 组
启动计算机的时候，需要启动大量的 Unit。如果每一次启动，都要一一写明本次启动需要哪些 Unit，显然非常不方便。Systemd 的解决方案就是 Target。
简单说，Target 就是一个 Unit 组，包含许多相关的 Unit 。启动某个 Target 的时候，Systemd 就会启动里面所有的 Unit。从这个意义上说，Target 这个概念类似于"状态点"，启动某个 Target 就好比启动到某种状态。
传统的 init 启动模式里面，有 RunLevel 的概念，跟 Target 的作用很类似。不同的是，RunLevel 是互斥的，不可能多个 RunLevel 同时启动，但是多个 Target 可以同时启动。
# 查看当前系统的所有 Target
root@node:/etc/systemd/system# systemctl list-unit-files --type=target
UNIT FILE STATE VENDOR PRESET
basic.target static enabled
bluetooth.target static enabled
initrd-switch-root.target static enabled
multi-user.target static enabled
network-online.target static enabled
# 查看一个 Target 包含的所有 Unit
root@node:/etc/systemd/system# systemctl list-dependencies multi-user.target
multi-user.target
● ├─dbus.service
● ├─delinux-entry-app.service
● ├─delinux-entry-sys.service
● ├─systemd-ask-password-wall.path
● ├─systemd-networkd.service
● ├─systemd-resolved.service
● ├─systemd-update-utmp-runlevel.service
● ├─systemd-user-sessions.service
● ├─basic.target
● │ ├─tmp.mount
● │ ├─paths.target
● │ ├─slices.target
● │ │ ├─-.slice
● │ │ └─system.slice
● │ ├─sockets.target
● │ │ ├─dbus.socket
● │ │ ├─systemd-initctl.socket
● │ │ ├─systemd-journald-audit.socket
● │ │ ├─systemd-journald-dev-log.socket
● │ │ ├─systemd-journald.socket
● │ │ ├─systemd-udevd-control.socket
● │ │ └─systemd-udevd-kernel.socket
● │ ├─sysinit.target
● │ │ ├─dev-hugepages.mount
● │ │ ├─dev-mqueue.mount
● │ │ ├─kmod-static-nodes.service
● │ │ ├─proc-sys-fs-binfmt_misc.automount
● │ │ ├─sys-fs-fuse-connections.mount
● │ │ ├─sys-kernel-config.mount
● │ │ ├─sys-kernel-debug.mount
● │ │ ├─sys-kernel-tracing.mount
● │ │ ├─systemd-ask-password-console.path
● │ │ ├─systemd-binfmt.service
● │ │ ├─systemd-boot-system-token.service
● │ │ ├─systemd-hwdb-update.service
● │ │ ├─systemd-journal-flush.service
● │ │ ├─systemd-journald.service
● │ │ ├─systemd-machine-id-commit.service
● │ │ ├─systemd-modules-load.service
● │ │ ├─systemd-pstore.service
● │ │ ├─systemd-random-seed.service
● │ │ ├─systemd-sysctl.service
● │ │ ├─systemd-sysusers.service
● │ │ ├─systemd-tmpfiles-setup-dev.service
● │ │ ├─systemd-tmpfiles-setup.service
● │ │ ├─systemd-udev-trigger.service
● │ │ ├─systemd-udevd.service
● │ │ ├─systemd-update-utmp.service
● │ │ ├─cryptsetup.target
● │ │ ├─local-fs.target
● │ │ │ └─systemd-remount-fs.service
● │ │ └─swap.target
● │ └─timers.target
● │ ├─e2scrub_all.timer
● │ ├─fstrim.timer
● │ ├─motd-news.timer
● │ └─systemd-tmpfiles-clean.timer
● ├─getty.target
● │ ├─getty-static.service
● │ ├─[email protected]
● │ └─[email protected]
● ├─nfs-client.target
● │ ├─nfs-blkmap.service
● │ ├─rpc-gssd.service
● │ └─remote-fs-pre.target
● ├─remote-fs.target
● │ └─nfs-client.target
● │ ├─nfs-blkmap.service
● │ ├─rpc-gssd.service
● │ └─remote-fs-pre.target
● └─zfs.target
# 查看启动时的默认 Target
root@node:/etc/systemd/system# systemctl get-default
graphical.target
# 设置启动时的默认 Target
systemctl set-default multi-user.target
# 切换 Target 时，默认不关闭前一个 Target 启动的进程，
# systemctl isolate 命令改变这种行为，
# 关闭前一个 Target 里面所有不属于后一个 Target 的进程
systemctl isolate multi-user.target
Target 与 传统 RunLevel 的对应关系如下：
Traditional runlevel New target name Symbolically linked to...
Runlevel 0 | runlevel0.target -> poweroff.target
Runlevel 1 | runlevel1.target -> rescue.target
Runlevel 2 | runlevel2.target -> multi-user.target
Runlevel 3 | runlevel3.target -> multi-user.target
Runlevel 4 | runlevel4.target -> multi-user.target
Runlevel 5 | runlevel5.target -> graphical.target
Runlevel 6 | runlevel6.target -> reboot.target
它与init进程的主要差别如下：
- 默认的 RunLevel（在/etc/inittab文件设置）现在被默认的 Target 取代，位置是 /etc/systemd/system/default.target，通常符号链接到graphical.target（图形界面）或者multi-user.target（多用户命令行）。
- 启动脚本的位置，以前是/etc/init.d目录，符号链接到不同的 RunLevel 目录（如/etc/rc3.d、/etc/rc5.d等），现在则存放在 /lib/systemd/system 和 /etc/systemd/system 目录。
- 配置文件的位置，以前init进程的配置文件是/etc/inittab，各种服务的配置文件存放在/etc/sysconfig目录。现在的配置文件主要存放在 /lib/systemd 目录，在 /etc/systemd 目录里面的修改可以覆盖原始设置。
root@node:/etc/systemd/system# ll /lib/systemd
total 8334
drwxr-xr-x 1 root root 4096 Nov 11 16:20 ./
drwxr-xr-x 1 root root 4096 May 31 2022 ../
drwxr-xr-x 3 root root 26 Nov 24 10:47 boot/
drwxr-xr-x 2 root root 339 Nov 24 10:47 catalog/
-rw-r--r-- 1 root root 2446488 Sep 8 2022 libsystemd-shared-245.so
drwxr-xr-x 2 root root 266 Nov 24 10:55 network/
drwxr-xr-x 2 root root 47 Nov 24 10:47 ntp-units.d/
-rw-r--r-- 1 root root 701 Sep 8 2022 resolv.conf
drwxr-xr-x 2 root root 39 Nov 24 10:51 scripts/
-rwxr-xr-x 1 root root 1246 Sep 8 2022 set-cpufreq*
drwxr-xr-x 1 root root 4096 Apr 23 11:49 system/
drwxr-xr-x 2 root root 452 Nov 24 18:51 system-generators/
drwxr-xr-x 2 root root 61 Nov 24 18:51 system-preset/
drwxr-xr-x 2 root root 3 Sep 8 2022 system-shutdown/
drwxr-xr-x 2 root root 3 Sep 8 2022 system-sleep/
-rwxr-xr-x 1 root root 1551488 Sep 8 2022 systemd*
-rwxr-xr-x 1 root root 10240 Sep 8 2022 systemd-ac-power*
-rwxr-xr-x 1 root root 22520 Sep 8 2022 systemd-backlight*
-rwxr-xr-x 1 root root 14408 Sep 8 2022 systemd-binfmt*
-rwxr-xr-x 1 root root 22632 Sep 8 2022 systemd-bless-boot*
-rwxr-xr-x 1 root root 10240 Sep 8 2022 systemd-boot-check-no-failures*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-cgroups-agent*
-rwxr-xr-x 1 root root 31024 Sep 8 2022 systemd-cryptsetup*
-rwxr-xr-x 1 root root 14448 Sep 8 2022 systemd-dissect*
-rwxr-xr-x 1 root root 22456 Sep 8 2022 systemd-fsck*
-rwxr-xr-x 1 root root 22528 Sep 8 2022 systemd-fsckd*
-rwxr-xr-x 1 root root 18432 Sep 8 2022 systemd-growfs*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-hibernate-resume*
-rwxr-xr-x 1 root root 26624 Sep 8 2022 systemd-hostnamed*
-rwxr-xr-x 1 root root 14336 Sep 8 2022 systemd-initctl*
-rwxr-xr-x 1 root root 149552 Sep 8 2022 systemd-journald*
-rwxr-xr-x 1 root root 38912 Sep 8 2022 systemd-localed*
-rwxr-xr-x 1 root root 252112 Sep 8 2022 systemd-logind*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-makefs*
-rwxr-xr-x 1 root root 14440 Sep 8 2022 systemd-modules-load*
-rwxr-xr-x 1 root root 30720 Sep 8 2022 systemd-network-generator*
-rwxr-xr-x 1 root root 2218920 Sep 8 2022 systemd-networkd*
-rwxr-xr-x 1 root root 26808 Sep 8 2022 systemd-networkd-wait-online*
-rwxr-xr-x 1 root root 18456 Sep 8 2022 systemd-pstore*
-rwxr-xr-x 1 root root 10240 Sep 8 2022 systemd-quotacheck*
-rwxr-xr-x 1 root root 18352 Sep 8 2022 systemd-random-seed*
-rwxr-xr-x 1 root root 18456 Sep 8 2022 systemd-remount-fs*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-reply-password*
-rwxr-xr-x 1 root root 399472 Sep 8 2022 systemd-resolved*
-rwxr-xr-x 1 root root 18432 Sep 8 2022 systemd-rfkill*
-rwxr-xr-x 1 root root 47168 Sep 8 2022 systemd-shutdown*
-rwxr-xr-x 1 root root 18576 Sep 8 2022 systemd-sleep*
-rwxr-xr-x 1 root root 22528 Sep 8 2022 systemd-socket-proxyd*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-sulogin-shell*
-rwxr-xr-x 1 root root 18584 Sep 8 2022 systemd-sysctl*
-rwxr-xr-x 1 root root 1360 Jul 20 2022 systemd-sysv-install*
-rwxr-xr-x 1 root root 14256 Sep 8 2022 systemd-time-wait-sync*
-rwxr-xr-x 1 root root 38984 Sep 8 2022 systemd-timedated*
-rwxr-xr-x 1 root root 47104 Sep 8 2022 systemd-timesyncd*
-rwxr-xr-x 1 root root 740368 Sep 8 2022 systemd-udevd*
-rwxr-xr-x 1 root root 14360 Sep 8 2022 systemd-update-utmp*
-rwxr-xr-x 1 root root 14280 Sep 8 2022 systemd-user-runtime-dir*
-rwxr-xr-x 1 root root 10160 Sep 8 2022 systemd-user-sessions*
-rwxr-xr-x 1 root root 14392 Sep 8 2022 systemd-veritysetup*
-rwxr-xr-x 1 root root 14256 Sep 8 2022 systemd-volatile-root*
drwxr-xr-x 3 root root 527 Nov 24 10:52 user/
drwxr-xr-x 2 root root 57 Nov 24 10:47 user-environment-generators/
drwxr-xr-x 2 root root 3 Sep 8 2022 user-generators/
drwxr-xr-x 2 root root 40 Nov 24 10:47 user-preset/
root@node:/etc/systemd/system# ll /etc/systemd/
total 27
drwxr-xr-x 1 root root 4096 Jan 6 14:34 ./
drwxr-xr-x 1 root root 4096 Jan 5 10:38 ../
-rw-r--r-- 1 root root 1029 Feb 20 11:32 journald.conf
-rw-r--r-- 1 root root 1042 Sep 8 2022 logind.conf
lrwxrwxrwx 1 root root 54 Nov 11 16:20 network -> /home/node/SysData/rw_rootfs/etc/systemd/network//
-rw-r--r-- 1 root root 584 Apr 2 2020 networkd.conf
-rw-r--r-- 1 root root 529 Apr 2 2020 pstore.conf
-rw-r--r-- 1 root root 642 Sep 8 2022 resolved.conf
-rw-r--r-- 1 root root 790 Apr 2 2020 sleep.conf
drwxr-xr-x 1 root root 4096 Apr 23 22:49 system/
-rw-r--r-- 1 root root 2180 Jan 31 10:32 system.conf
lrwxrwxrwx 1 root root 60 Nov 11 16:20 timesyncd.conf -> /home/node/SysData/rw_rootfs/etc/systemd/timesyncd.conf
drwxr-xr-x 2 root root 3 Sep 8 2022 user/
-rw-r--r-- 1 root root 1185 Sep 8 2022 user.conf
六、journalctl
Systemd 统一管理所有 Unit 的启动日志。带来的好处就是，可以只用 journalctl 一个命令，查看所有日志（内核日志和应用日志）。日志的配置文件是 /etc/systemd/journald.conf。用法如下：
# 查看所有日志（默认情况下 ，只保存本次启动的日志）
journalctl
# 查看内核日志（不显示应用日志）
journalctl -k
# 查看系统本次启动的日志
journalctl -b
journalctl -b -0
# 查看上一次启动的日志（需更改设置）
journalctl -b -1
# 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"
# 显示尾部的最新10行日志
journalctl -n
# 显示尾部指定行数的日志
journalctl -n 20
# 实时滚动显示最新日志
journalctl -f
# 查看指定服务的日志
journalctl /usr/lib/systemd/systemd
# 查看指定进程的日志
journalctl _PID=1
# 查看某个路径的脚本的日志
journalctl /usr/bin/bash
# 查看指定用户的日志
journalctl _UID=33 --since today
# 查看某个 Unit 的日志
journalctl -u nginx.service
journalctl -u nginx.service --since today
# 实时滚动显示某个 Unit 的最新日志
journalctl -u nginx.service -f
# 合并显示多个 Unit 的日志
$ journalctl -u nginx.service -u php-fpm.service --since today
# 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 -p err -b
# 日志默认分页输出，--no-pager 改为正常的标准输出
journalctl --no-pager
# 以 JSON 格式（单行）输出
journalctl -b -u nginx.service -o json
# 以 JSON 格式（多行）输出，可读性更好
journalctl -b -u nginx.serviceqq
-o json-pretty
# 显示日志占据的硬盘空间
journalctl --disk-usage
# 指定日志文件占据的最大空间
journalctl --vacuum-size=1G
# 指定日志文件保存多久
journalctl --vacuum-time=1years
七、启动
7.1 开机启动
对于那些支持 Systemd 的软件，安装的时候，会自动在/usr/lib/systemd/system目录添加一个配置文件。
如果你想让该软件开机启动，则 systemctl enable httpd 。这相当于在/etc/systemd/system目录添加一个符号链接，指向/usr/lib/systemd/system里面的httpd.service文件。
这是因为开机时，Systemd只执行/etc/systemd/system目录里面的配置文件。这也意味着，如果把修改后的配置文件放在该目录，就可以达到覆盖原始配置的效果。
7.2 启停服务
设置开机启动以后，软件并不会立即启动，必须等到下一次开机。如果想现在就运行该软件，那么要执行 systemctl start httpd。
执行上面的命令以后，有可能启动失败，因此要用systemctl status命令查看一下该服务的状态，其输出内容如下:
- Loaded行：配置文件的位置，是否设为开机启动
- Active行：表示正在运行
- Main PID行：主进程 ID
- Status行：由应用本身（这里是 httpd ）提供的软件当前状态
- CGroup块：应用的所有子进程
- 日志块：应用的日志
systemctl status httpd
httpd.service - The Apache HTTP Server
Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled)
Active: active (running) since 金 2014-12-05 12:18:22 JST; 7min ago
Main PID: 4349 (httpd)
Status: "Total requests: 1; Current requests/sec: 0; Current traffic: 0 B/sec"
CGroup: /system.slice/httpd.service
├─4349 /usr/sbin/httpd -DFOREGROUND
├─4350 /usr/sbin/httpd -DFOREGROUND
├─4351 /usr/sbin/httpd -DFOREGROUND
├─4352 /usr/sbin/httpd -DFOREGROUND
├─4353 /usr/sbin/httpd -DFOREGROUND
└─4354 /usr/sbin/httpd -DFOREGROUND
12月 05 12:18:22 localhost.localdomain systemd[1]: Starting The Apache HTTP Server...
12月 05 12:18:22 localhost.localdomain systemd[1]: Started The Apache HTTP Server.
12月 05 12:22:40 localhost.localdomain systemd[1]: Started The Apache HTTP Server.
终止正在运行的服务，需要执行 systemctl stop httpd.service。有时该命令可能没有响应，服务停不下来。这时候就不得不"杀进程"了，向正在运行的进程发出kill信号：systemctl kill httpd.service。
此外，重启服务要执行 systemctl restart httpd.service