在Linux上学习现代服务管理系统(Systemd)

2024-04-25 09:47:03 114

systemd是Linux操作系统的框架和服务管理器。在作为引导的第一个进程（如PID1）继续运行时，它将作为init系统运行。可以提高和保持用户空间服务。本文介绍-“学习Linux上的现代服务管理系统(Systemd)”

要获取有关systemd的更多信息，请使用以下命令，如下所示–

$ systemd -h

样本输出应如下所示–

Starts up and maintains the system or user services.

-h --help                                           Show this help
--test                                              Determine startup sequence, dump it and exit
--no-pager                                          Do not pipe output into a pager
--dump-configuration-items                          Dump understood unit configuration items
--unit=UNIT                                         Set default unit
--system                                            Run a system instance, even if PID != 1
--user                                              Run a user instance
--dump-core[=BOOL]                                  Dump core on crash
--crash-vt=NR                                       Change to specified VT on crash
--crash-reboot[=BOOL]                               Reboot on crash
--crash-shell[=BOOL]                                Run shell on crash
.......................................................................................

版本信息

要获取有关systemd的版本信息，请使用以下命令，如下所示–

$ systemd --version

样本输出应如下所示–

systemd 229
+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP
+GCRYPT +GNUTLS +ACL +XZ -LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN

确定启动顺序

要确定启动顺序，请使用以下命令，如下所示–

$ systemd --test

样本输出应如下所示–

State Change Timestamp: Mon 2017-01-30 11:15:37 IST
               Inactive Exit Timestamp: Mon 2017-01-30 11:15:37 IST
               Active Enter Timestamp: Mon 2017-01-30 11:15:37 IST
               Active Exit Timestamp: n/a
               Inactive Enter Timestamp: n/a
               GC Check Good: yes
               Need Daemon Reload: no
               Transient: no
               Slice: n/a
               CGroup: n/a
               CGroup realized: no
               CGroup mask: 0x0
               CGroup members mask: 0x0
               Name: sys-devices-platform-serial8250-tty-ttyS26.device
               Following Set Member: dev-ttyS26.device
               Job Timeout: 1min 30s
..............................................................................

了解单元配置

要获取转储并了解单元配置项，请使用以下命令–

$ systemd --dump-configuration-items

样本输出应如下所示–

[Scope]
Slice=SLICE
CPUAccounting=BOOLEAN
CPUShares=SHARES
StartupCPUShares=SHARES
CPUQuota=OTHER
MemoryAccounting=BOOLEAN
MemoryLimit=LIMIT
DeviceAllow=DEVICE
DevicePolicy=POLICY
BlockIOAccounting=BOOLEAN
BlockIOWeight=WEIGHT
StartupBlockIOWeight=WEIGHT
BlockIODeviceWeight=DEVICEWEIGHT
BlockIOReadBandwidth=BANDWIDTH
.....................................................................................

分析系统启动过程

要分析系统引导过程，请使用以下命令–

$ systemd-analyze

样本输出应如下所示–

Startup finished in 8.740s (firmware) + 4.483s (loader) + 3.616s (kernel) + 4min 21.244s (userspace) = 4min 38.084s

引导过程列表

要获取列表启动过程及其时间，请使用以下命令，如下所示：

$ systemd-analyze blame

样本输出应如下所示–

3min 59.399s apt-daily.service
      16.585s NetworkManager-wait-online.service
      11.182s grub-common.service
      9.532s apport.service
      9.224s irqbalance.service
      8.986s networking.service
      8.916s snapd.refresh.service
      8.859s speech-dispatcher.service
      7.709s dev-sda2.device
      7.641s gpu-manager.service
      7.641s rsyslog.service
      7.078s avahi-daemon.service
      6.178s lightdm.service
..............................................................................

控制组内容

要显示控制组内容，请使用以下命令，如下所示–

$ systemd-cgls

样本输出应如下所示–

Control group /:
-.slice
├─init.scope
│ └─1 /lib/systemd/systemd --system --deserialize 19
├─system.slice
│ ├─avahi-daemon.service
│ │ ├─733 avahi-daemon: running [linux-Inspiron-3542.local
│ │ └─806 avahi-daemon: chroot helpe
│ ├─thermald.service
│ │ └─845 /usr/sbin/thermald --no-daemon --dbus-enable
│ ├─dbus.service
│ │ ├─ 759 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activ
│ │ └─2637 /usr/lib/x86_64-linux-gnu/fwupd/fwupd
│ ├─ModemManager.service
│ │ └─871 /usr/sbin/ModemManager
│ ├─cron.service
│ │ └─850 /usr/sbin/cron -f
│ ├─apache2.service
│ │ ├─ 4441 /usr/sbin/apache2 -k start

最高控制组

要按资源使用量显示最高控制组，请使用以下命令，如下所示–

$sudo systemd-cgtop

样本输出应如下所示–

Control Group                         Tasks          %CPU          Memory          Input/s       Output/s
/                                       -         20.0              6.3G             -               -
/init.scope                             1          -                 -               -               -
/system.slice                         125          -                 -               -               -
/user.slice                           695          -                 -               -               -
/user.slice/user-1000.slice           654          -                 -               -               -
/user.slice/user-126.slice             41          -                 -               -               -

系统控制

Systemctl可用于自省和管理“systemd”系统和服务管理器的状态。

要获取有关systemctl的更多信息，请使用以下命令，如下所示–

$ systemctl --help

样本输出应如下所示–

Query or send control commands to the systemd manager.

-h --help             Show this help
--version             Show package version
--system              Connect to system manager
--user                Connect to user service 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
...........................................................................

版本信息

要获取systemctl的版本，请使用以下命令–

$ systemctl --version

样本输出应如下所示–

systemd 229
+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP
+GCRYPT +GNUTLS +ACL +XZ -LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN

所有服务列表

要获取所有正在运行的服务的列表，请使用以下命令，如下所示–

$ systemctl

样本输出应如下所示–

UNIT LOAD ACTIVE SUB DESCRIPTION
proc-sys-fs-binfmt_misc.automount loaded active running Arbitrary Executable File Formats F
sys-devices-pci0000:00-0000:00:02.0-drm-card0-card0\x2deDP\x2d1-intel_backlight.device loaded
sys-devices-pci0000:00-0000:00:03.0-sound-card0.device loaded active plugged Haswell-ULT HD
sys-devices-pci0000:00-0000:00:1b.0-sound-card1.device loaded active plugged 8 Series HD Aud
sys-devices-pci0000:00-0000:00:1c.2-0000:06:00.0-net-wlp6s0.device loaded active plugged QCA
sys-devices-pci0000:00-0000:00:1c.3-0000:07:00.0-net-enp7s0.device loaded active plugged RTL
sys-devices-pci0000:00-0000:00:1d.0-usb1-1\x2d1-1\x2d1.6-1\x2d1.6:1.0-bluetooth-hci0.device lo
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda1.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda2.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda3.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda.device loaded act
sys-devices-pci0000:00-0000:00:1f.2-ata2-host1-target1:0:0-1:0:0:0-block-sr0.device loaded act
sys-devices-platform-dell\x2dlaptop-leds-dell::kbd_backlight.device loaded active plugged /s
sys-devices-platform-serial8250-tty-ttyS0.device loaded active plugged /sys/devices/platform
sys-devices-platform-serial8250-tty-ttyS1.device loaded active plugged /sys/devices/platform
sys-devices-platform-serial8250-tty-ttyS10.device loaded active plugged /sys/devices/platfor
sys-devices-platform-serial8250-tty-ttyS11.device loaded active plugged /sys/devices/platfor
sys-devices-platform-serial8250-tty-ttyS12.device loaded active plugged /sys/devices/platfor
sys-devices-platform-serial8250-tty-ttyS13.device loaded active plugged /sys/devices/platfor

启动服务

要使用systemctl启动服务，请使用以下命令，如下所示–

$ sudo systemctl start application.service

使用systemctl启动服务的示例示例如下所示–

$ sudo systemctl start bluetooth.service

服务状态

要获取bluetooth.service的状态，如下所示–

$ systemctl status bluetooth

样本输出应如下所示–

bluetooth.service - Bluetooth service
Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2017-01-27 09:32:45 IST; 3 days ago
Docs: man:bluetoothd(8)
Main PID: 954 (bluetoothd)
Status: "Running"
CGroup: /system.slice/bluetooth.service
└─954 /usr/lib/bluetooth/bluetoothd

Jan 30 10:10:22 linux-Inspiron-3542 bluetoothd[954]: gatt-time-server: Input/output error (5)
Jan 30 10:10:22 linux-Inspiron-3542 bluetoothd[954]: Not enough free handles to register service
Jan 30 10:10:22 linux-Inspiron-3542 bluetoothd[954]: Not enough free handles to register service
Jan 30 10:10:22 linux-Inspiron-3542 bluetoothd[954]: Sap driver initialization failed.
Jan 30 10:10:22 linux-Inspiron-3542 bluetoothd[954]: sap-server: Operation not permitted (1)
Jan 30 10:10:22 linux-Inspiron-3542 bluetoothd[954]: Endpoint registered: sender=:1.68 path=/Med
Jan 30 10:10:22 linux-Inspiron-3542 bluetoothd[954]: Endpoint registered: sender=:1.68 path=/Med
Jan 30 11:20:54 linux-Inspiron-3542 systemd[1]: Started Bluetooth service.
Jan 30 11:21:07 linux-Inspiron-3542 systemd[1]: Started Bluetooth service.
Jan 30 11:41:00 linux-Inspiron-3542 systemd[1]: Started Bluetooth service.

停止服务

要停止服务，请使用以下命令，如下所示–

$ sudo systemctl stop bluetooth.service

要验证上述命令，请使用以下命令，如下所示–

$ systemctl status bluetooth

样本输出应如下所示–

bluetooth.service - Bluetooth service
  Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
  Active: inactive (dead) since Mon 2017-01-30 11:45:35 IST; 4s ago
    Docs: man:bluetoothd(8)
Main PID: 954 (code=exited, status=0/SUCCESS)
Status: "Quitting"
..................................................................................

重新启动服务

要重新启动服务，请使用以下命令，如下所示–

$ sudo systemctl restart bluetooth.service

启用服务

要使服务能够在启动时启动，请使用以下命令，如下所示：

$ sudo systemctl enable bluetooth.service

取消服务

要禁用在启动时启动的服务，请使用以下命令，如下所示–

$ sudo systemctl disable bluetooth.service

要验证是否启用了服务，请使用以下命令，如下所示–

$ sudo systemctl is-enabled bluetooth.service; echo $?

样本输出应如下所示–

enabled
0

掩盖服务

要屏蔽服务，请使用以下命令，如下所示–

$ sudo systemctl mask bluetooth.service

取消屏蔽服务

要取消屏蔽服务，请使用以下命令，如下所示–

$ sudo systemctl unmask bluetooth.service

取消服务

要终止服务，请使用以下命令，如下所示–

$ sudo systemctl kill bluetooth.service

配置细节

要获取服务的配置详细信息，请使用以下命令，如下所示–

$ sudo systemctl show bluetooth

样本输出应如下所示–

Restart=no
NotifyAccess=none
RestartUSec=100ms
TimeoutStartUSec=1min 30s
TimeoutStopUSec=1min 30s
RuntimeMaxUSec=infinity
WatchdogUSec=0
WatchdogTimestampMonotonic=0
............................................................

分析关键链服务

要分析服务的关键链，请使用以下命令，如下所示：

$ sudo systemd-analyze critical-chain bluetooth.service

样本输出应如下所示–

The time after the unit is active or started is printed after the "@" character.
The time the unit takes to start is printed after the "+" character.

bluetooth.service +886ms

依附列表

要获取依赖项列表，请使用以下命令，如下所示–

$ sudo systemctl list-dependencies bluetooth.service

列出特定类型的单位

要获取特定类型的列表单位，请使用以下命令，如下所示–

systemctl -t mount

样本输出应如下所示–

UNIT                           LOAD                ACTIVE          SUB                DESCRIPTION
-.mount                        loaded             active          mounted                /
boot-efi.mount                 loaded             active          mounted                /boot/efi
dev-hugepages.mount            loaded             active          mounted                Huge Pages File System
dev-mqueue.mount               loaded             active          mounted                POSIX Message Queue File System
proc-sys-fs-binfmt_misc.mount  loaded             active          mounted                Arbitrary Executable File Formats File Syste
run-user-1000-gvfs.mount       loaded             active          mounted                /run/user/1000/gvfs
run-user-1000.mount            loaded             active          mounted                /run/user/1000
run-user-126.mount             loaded             active          mounted                /run/user/126
sys-fs-fuse-connections.mount  loaded             active          mounted                FUSE Control File System
sys-kernel-debug.mount         loaded             active          mounted                Debug File System
....................................................................

所有装载单位

要显示所有已加载的单位/属性，包括空/空，请使用以下命令，如下所示：

$ systemctl -a

样本输出应如下所示–

UNIT LOAD ACTIVE SUB DESCRIPTION
proc-sys-fs-binfmt_misc.automount loaded active running Arbitrary Executable File Forma
● org.freedesktop.network1.busname not-found inactive dead org.freedesktop.network1.busnam
dev-cdrom.device loaded active plugged HL-DT-ST_DVD+_-RW_GU90N
dev-cdrw.device loaded active plugged HL-DT-ST_DVD+_-RW_GU90N
dev-disk-by\x2did-ata\x2dHL\x2dDT\x2dST_DVD\x2b_\x2dRW_GU90N_M7FE9H30316.device loaded acti
dev-disk-by\x2did-ata\x2dTOSHIBA_MQ01ABD100_X4P6SQD0S.device loaded active plugged TOSH
dev-disk-by\x2did-ata\x2dTOSHIBA_MQ01ABD100_X4P6SQD0S\x2dpart1.device loaded active plugg
dev-disk-by\x2did-ata\x2dTOSHIBA_MQ01ABD100_X4P6SQD0S\x2dpart2.device loaded active plugg
dev-disk-by\x2did-ata\x2dTOSHIBA_MQ01ABD100_X4P6SQD0S\x2dpart3.device loaded active plugg
dev-disk-by\x2did-wwn\x2d0x50000395d5887d4c.device loaded active plugged TOSHIBA_MQ01AB
dev-disk-by\x2did-wwn\x2d0x50000395d5887d4c\x2dpart1.device loaded active plugged TOSHI
dev-disk-by\x2did-wwn\x2d0x50000395d5887d4c\x2dpart2.device loaded active plugged TOSHI
dev-disk-by\x2did-wwn\x2d0x50000395d5887d4c\x2dpart3.device loaded active plugged TOSHI
dev-disk-by\x2did-wwn\x2d0x5001480000000000.device loaded active plugged HL-DT-ST_DV
..............................................................................................

单位文件列表

要获取单位文件列表，请使用以下命令，如下所示–

$ systemctl list-unit-files

样本输出应如下所示–

UNIT FILE                                   STATE
proc-sys-fs-binfmt_misc.automount           static
dev-hugepages.mount                         static
dev-mqueue.mount                            static
proc-sys-fs-binfmt_misc.mount               static
sys-fs-fuse-connections.mount               static
sys-kernel-config.mount                     static
sys-kernel-debug.mount                      static
acpid.path                                  enabled
cups.path                                   enabled
systemd-ask-password-console.path           static
systemd-ask-password-plymouth.path          static
systemd-ask-password-wall.path              static
systemd-networkd-resolvconf-update.path     static
accounts-daemon.service                     enabled
acpid.service                               disabled
alsa-restore.service                        static
alsa-state.service                          static
alsa-utils.service                          masked
anacron-resume.service                      enabled
anacron.service                             enabled
.................................................

指定单位文件列表

要获取指定单位文件的列表，请使用以下命令，如下所示–

$ sudo systemctl list-unit-files --type=moun

样本输出应如下所示–

UNIT FILE                              STATE
dev-hugepages.mount                    static
dev-mqueue.mount                       static
proc-sys-fs-binfmt_misc.mount          static
sys-fs-fuse-connections.mount          static
sys-kernel-config.mount                static
sys-kernel-debug.mount                 static

6 unit files listed.
......................................................

主机和本地容器的单位列表

要显示主机和本地容器的单元列表，请使用以下命令，如下所示–

$ sudo systemctl -r

样本输出应如下所示–

UNIT LOAD ACTIVE SUB DESCRIPTION
proc-sys-fs-binfmt_misc.automount loaded active running Arbitrary Executable File Formats F
sys-devices-pci0000:00-0000:00:02.0-drm-card0-card0\x2deDP\x2d1-intel_backlight.device loaded
sys-devices-pci0000:00-0000:00:03.0-sound-card0.device loaded active plugged Haswell-ULT HD
sys-devices-pci0000:00-0000:00:1b.0-sound-card1.device loaded active plugged 8 Series HD Aud
sys-devices-pci0000:00-0000:00:1c.2-0000:06:00.0-net-wlp6s0.device loaded active plugged QCA
sys-devices-pci0000:00-0000:00:1c.3-0000:07:00.0-net-enp7s0.device loaded active plugged RTL
sys-devices-pci0000:00-0000:00:1d.0-usb1-1\x2d1-1\x2d1.6-1\x2d1.6:1.0-bluetooth-hci0.device lo
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda1.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda2.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda3.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda.device loaded act
sys-devices-pci0000:00-0000:00:1f.2-ata2-host1-target1:0:0-1:0:0:0-block-sr0.device loaded act
sys-devices-platform-dell\x2dlaptop-leds-dell::kbd_backlight.device loaded active plugged
............................................................................................

排队的工作

要指定如何处理已排队的作业，请在排队新作业时使用以下命令，如下所示：

$ systemctl --job-mode=active

样本输出应如下所示–

UNIT LOAD ACTIVE SUB DESCRIPTION
proc-sys-fs-binfmt_misc.automount loaded active running Arbitrary Executable File Formats F
sys-devices-pci0000:00-0000:00:02.0-drm-card0-card0\x2deDP\x2d1-intel_backlight.device loaded
sys-devices-pci0000:00-0000:00:03.0-sound-card0.device loaded active plugged Haswell-ULT HD
sys-devices-pci0000:00-0000:00:1b.0-sound-card1.device loaded active plugged 8 Series HD Aud
sys-devices-pci0000:00-0000:00:1c.2-0000:06:00.0-net-wlp6s0.device loaded active plugged QCA
sys-devices-pci0000:00-0000:00:1c.3-0000:07:00.0-net-enp7s0.device loaded active plugged RTL
sys-devices-pci0000:00-0000:00:1d.0-usb1-1\x2d1-1\x2d1.6-1\x2d1.6:1.0-bluetooth-hci0.device lo
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda1.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda2.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda3.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda.device loaded act
sys-devices-pci0000:00-0000:00:1f.2-ata2-host1-target1:0:0-1:0:0:0-block-sr0.device loaded act
sys-devices-platform-dell\x2dlaptop-leds-dell::kbd_backlight.device loaded active plugged /s
sys-devices-platform-serial8250-tty-ttyS0.device loaded active plugged /sys/devices/platform
sys-devices-platform-serial8250-tty-ttyS1.device loaded active plugged /sys/devices/platform
sys-devices-platform-serial8250-tty-ttyS10.device loaded active plugged /sys/devices/platfor
sys-devices-platform-serial8250-tty-ttyS11.device loaded active plugged /sys/devices/platfor
sys-devices-platform-serial8250-tty-ttyS12.device loaded active plugged /sys/devices/platfor
sys-devices-platform-serial8250-tty-ttyS13.device loaded active plugged /sys/devices/platfor
sys-devices-platform-serial8250-tty-ttyS14.device loaded active plugged /sys/devices/plat
..............................................................................................

插座类型

要获取所有套接字类型，请使用以下命令，如下所示–

$ systemctl --show-types

样本输出应如下所示–

UNIT LOAD ACTIVE SUB DESCRIPTION
proc-sys-fs-binfmt_misc.automount loaded active running Arbitrary Executable File Formats F
sys-devices-pci0000:00-0000:00:02.0-drm-card0-card0\x2deDP\x2d1-intel_backlight.device loaded
sys-devices-pci0000:00-0000:00:03.0-sound-card0.device loaded active plugged Haswell-ULT HD
sys-devices-pci0000:00-0000:00:1b.0-sound-card1.device loaded active plugged 8 Series HD Aud
sys-devices-pci0000:00-0000:00:1c.2-0000:06:00.0-net-wlp6s0.device loaded active plugged QCA
sys-devices-pci0000:00-0000:00:1c.3-0000:07:00.0-net-enp7s0.device loaded active plugged RTL
sys-devices-pci0000:00-0000:00:1d.0-usb1-1\x2d1-1\x2d1.6-1\x2d1.6:1.0-bluetooth-hci0.device lo
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda1.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda2.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda3.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda.device loaded act
sys-devices-pci0000:00-0000:00:1f.2-ata2-host1-target1:0:0-1:0:0:0-block-sr0.device loaded act
sys-devices-platform-dell\x2dlaptop-leds-dell::kbd_backlight.device loaded active plugged /s
sys-devices-platform-serial8250-tty-ttyS0.device loaded active plugged /sys/devices/platform
sys-devices-platform-serial8250-tty-ttyS1.device loaded active plugged /sys/devices/platf
........................................................................................

忽略抑制剂

关闭或睡眠时要忽略抑制物。使用以下命令，如下所示–

$ systemctl -i

样本输出应如下所示–

UNIT LOAD ACTIVE SUB DESCRIPTION
proc-sys-fs-binfmt_misc.automount loaded active running Arbitrary Executable File Formats F
sys-devices-pci0000:00-0000:00:02.0-drm-card0-card0\x2deDP\x2d1-intel_backlight.device loaded
sys-devices-pci0000:00-0000:00:03.0-sound-card0.device loaded active plugged Haswell-ULT HD
sys-devices-pci0000:00-0000:00:1b.0-sound-card1.device loaded active plugged 8 Series HD Aud
sys-devices-pci0000:00-0000:00:1c.2-0000:06:00.0-net-wlp6s0.device loaded active plugged QCA
sys-devices-pci0000:00-0000:00:1c.3-0000:07:00.0-net-enp7s0.device loaded active plugged RTL
sys-devices-pci0000:00-0000:00:1d.0-usb1-1\x2d1-1\x2d1.6-1\x2d1.6:1.0-bluetooth-hci0.device lo
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda1.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda2.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda3.device loade
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda.device loaded act
sys-devices-pci0000:00-0000:00:1f.2-ata2-host1-target1:0:0-1:0:0:0-block-sr0.device loaded act
sys-devices-platform-dell\x2dlaptop-leds-dell::kbd_backlight.device loaded active plugged /s
sys-devices-platform-serial8250-tty-ttyS0.device loaded active plugged /sys/devices/platform
sys-devices-platform-serial8250-tty-ttyS1.device loaded active plugged /sys/devices/platform
sys-devices-platform-serial8250-tty-ttyS10.device loaded active plugged /sys/devices/platfor
sys-devices-platform-serial8250-tty-ttyS11.device loaded active plugged /sys/devices/platfor
sys-devices-platform-serial8250-tty-ttyS12.device loaded active plugged /sys/devices/platfor
sys-devices-platform-serial8250-tty-ttyS13.device loaded active plugged /sys/devices/plat
............................................................................................

套接字信息列表

要获取套接字信息列表，请使用以下命令，如下所示

$sudo systemctl list-unit-files --type=socket

样本输出应如下所示–

UNIT FILE                     STATE
acpid.socket                  enabled
apport-forward.socket         enabled
avahi-daemon.socket           enabled
cups.socket                   enabled
dbus.socket                   static
saned.socket                  disabled
snapd.socket                  enabled
syslog.socket                 static
systemd-bus-proxyd.socket     static
systemd-fsckd.socket          static
systemd-initctl.socket        static
........................................................................

启用套接字

要启用套接字，请使用以下命令，如下所示–

$ sudo systemctl start saned.socket

在上面的命令中，saned.socket是单位文件。

停止插座

要停止套接字，请使用以下命令，如下所示–

$ sudo systemctl stop saned.socket

重新启动套接字

要重新启动套接字，请使用以下命令，如下所示–

$ sudo systemctl restart saned.socket

重新装上插座

要重新加载套接字，请使用以下命令，如下所示–

$ sudo systemctl reload saned.socket

启用套接字

要启用套接字，请使用以下命令，如下所示–

$ sudo systemctl enable saned.socket

禁用套接字

要禁用套接字，请使用以下命令，如下所示–

$ sudo systemctl disable saned.socket

掩盖插座

要屏蔽套接字，请使用以下命令，如下所示–

$ sudo systemctl mask saned.socket

揭开插座的面罩

要取消屏蔽该套接字，请使用以下命令，如下所示–

$ sudo systemctl unmask saned.socket

插座状态

要获取套接字的状态，请使用以下命令，如下所示–

$ sudo systemctl status saned.socket

样本输出应如下所示–

saned.socket - saned incoming socket
   Loaded: loaded (/lib/systemd/system/saned.socket; disabled; vendor preset: enabled)
   Active: active (listening) since Mon 2017-01-30 12:30:05 IST; 2min 59s ago
   Listen: [::]:6566 (Stream)
Accepted: 0; Connected: 0

Jan 30 12:30:05 linux-Inspiron-3542 systemd[1]: Listening on saned incoming socket.

重新启动系统

要重新引导系统，请使用以下命令，如下所示–

$sudo systemctl reboot

挂起系统

要挂起系统，请使用以下命令，如下所示–

$sudo systemctl suspend

休眠系统

要使系统休眠，请使用以下命令，如下所示–

$sudo systemctl hibernate

关闭系统

要关闭系统，请使用以下命令，如下所示–

$ sudo systemctl poweroff

关机系统

要关闭系统，请使用以下命令，如下所示–

$sudo systemctl halt

在本文中，我们了解了–学习Linux上的现代服务管理系统(Systemd)，我们将提供更多基于Linux的技巧和窍门。继续阅读！

在Linux上学习现代服务管理系统(Systemd)

版本信息

确定启动顺序

了解单元配置

分析系统启动过程

引导过程列表

控制组内容

最高控制组

系统控制

版本信息

所有服务列表

启动服务

服务状态

停止服务

重新启动服务

启用服务

取消服务

掩盖服务

取消屏蔽服务

取消服务

配置细节

分析关键链服务

依附列表

列出特定类型的单位

所有装载单位

单位文件列表

指定单位文件列表

主机和本地容器的单位列表

排队的工作

插座类型

忽略抑制剂

套接字信息列表

启用套接字

停止插座

重新启动套接字

重新装上插座

启用套接字

禁用套接字

掩盖插座

揭开插座的面罩

插座状态

重新启动系统

挂起系统

休眠系统

关闭系统

关机系统

热门推荐

随机推荐