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10.23 linux任务计划cron
我们可能有这样的需求:在凌晨的时候做一些操作,例如备份数据、重启服务等。这样就需要借助任务计划去实现。
linux的任务计划服务:cron。cron的配置文件定义了执行的SHELL,执行命令的PATH等,还定义了时间的格式。
[root@lgs ~]# cat /etc/crontab
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
# For details see man 4 crontabs
# Example of job definition:
# .---------------- minute (0 - 59)
# | .------------- hour (0 - 23)
# | | .---------- day of month (1 - 31)
# | | | .------- month (1 - 12) OR jan,feb,mar,apr ...
# | | | | .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# | | | | |
# * * * * * user-name command to be executed
编辑任务计划:crontab -e,像vim一样的操作进行编辑。
[root@lgs ~]# crontab -e
no crontab for root - using an empty one
0 3 * * * /bin/bash /usr/123.sh >>/tmp/123.log 2>>/tmp/123.log
crontab: installing new crontab
[root@lgs ~]# cat /var/spool/cron/root
0 3 * * * /bin/bash /usr/123.sh >>/tmp/123.log 2>>/tmp/123.log
每月的1-10号执行:
0 3 1-10 * * /bin/bash /usr/123.sh >>/tmp/123.log 2>>/tmp/123.log
双月份执行:
0 3 * */2 * /bin/bash /usr/123.sh >>/tmp/123.log 2>>/tmp/123.log
双月份的周2、周5执行,用逗号分割:
0 3 * */2 2,5 /bin/bash /usr/123.sh >>/tmp/123.log 2>>/tmp/123.log
确保cron会执行,要启动crond服务:
[root@lgs ~]# systemctl start crond
[root@lgs ~]# systemctl status crond
● crond.service - Command Scheduler
Loaded: loaded (/usr/lib/systemd/system/crond.service; enabled; vendor preset: enabled)
Active: active (running) since 日 2018-05-13 11:47:51 CST; 10min ago
Main PID: 572 (crond)
CGroup: /system.slice/crond.service
└─572 /usr/sbin/crond -n
5月 13 11:47:51 lgs systemd[1]: Started Command Scheduler.
5月 13 11:47:51 lgs systemd[1]: Starting Command Scheduler...
5月 13 11:47:51 lgs crond[572]: (CRON) INFO (RANDOM_DELAY will be scaled with factor 74% if used.)
5月 13 11:47:51 lgs crond[572]: (CRON) INFO (running with inotify support)
为什么有些时候,写了计划,就是没有按计划执行:
可能是脚本里的命令,没有用到绝对路径。这是因为crontab的配置文件里定义的PATH,没有你执行的命令的路径。解决办法就是执行的脚本命令要写绝对路径,要么把命令的绝对路径加入到crontab的配置文件里的PATH中去。
一般尽量别修改配置文件,而是命令用绝对路径编写比较好。
任务计划要追加执行日志,方便以后可查,养成好的习惯。
列出系统的任务计划:
[root@lgs ~]# crontab -l
0 3 * * * /bin/bash /usr/123.sh >>/tmp/123.log 2>>/tmp/123.log
备份任务计划:备份文件即可,一般以用户的名字命名的cron文件。
[root@lgs ~]# ls -l /var/spool/cron/
总用量 4
-rw------- 1 root root 63 5月 13 11:54 root
-u选项:指定用户。不指定默认是root。
[root@lgs ~]# crontab -u root -l
0 3 * * * /bin/bash /usr/123.sh >>/tmp/123.log 2>>/tmp/123.log
[root@lgs ~]# crontab -u lgs -l
no crontab for lgs
-r选项:删除计划
[root@lgs ~]# crontab -r
[root@lgs ~]# crontab -u root -l
no crontab for root
10.24 chkconfig工具
系统里像crond、iptables、nginx、httpd、mysql都是服务的形式运行。系统怎么去控制管理这些服务的启动、开机启动、指定级别开机启动等。就要用到chkconfig。
linux的系统服务管理:CentOS 5、6的时候使用chkconfig。
CentOS7也可以用chkconfig,但是比较少用,主要用systemd来管理服务。
列出服务:用chkconfig只列出用chkconfig管理的服务,即sysV机制的,不含systemd管理的
[root@lgs ~]# chkconfig --list
注:该输出结果只显示 SysV 服务,并不包含
原生 systemd 服务。SysV 配置数据
可能被原生 systemd 配置覆盖。
要列出 systemd 服务,请执行 'systemctl list-unit-files'。
查看在具体 target 启用的服务请执行
'systemctl list-dependencies [target]'。
mysqld 0:关 1:关 2:开 3:开 4:开 5:开 6:关
netconsole 0:关 1:关 2:关 3:关 4:关 5:关 6:关
network 0:关 1:关 2:开 3:开 4:开 5:开 6:关
CentOS 5、6:进程id为1 的是init(sysV机制),在/etc/init.d/ 下
CentOS7:进程id为1 的是 systemd。
某服务关闭开机启动:(针对2345级别,因为016级别开机启动没意义)
[root@lgs ~]# chkconfig --list
注:该输出结果只显示 SysV 服务,并不包含
原生 systemd 服务。SysV 配置数据
可能被原生 systemd 配置覆盖。
要列出 systemd 服务,请执行 'systemctl list-unit-files'。
查看在具体 target 启用的服务请执行
'systemctl list-dependencies [target]'。
mysqld 0:关 1:关 2:开 3:开 4:开 5:开 6:关
netconsole 0:关 1:关 2:关 3:关 4:关 5:关 6:关
network 0:关 1:关 2:开 3:开 4:开 5:开 6:关
[root@lgs ~]# chkconfig mysqld off
[root@lgs ~]# chkconfig --list
注:该输出结果只显示 SysV 服务,并不包含
原生 systemd 服务。SysV 配置数据
可能被原生 systemd 配置覆盖。
要列出 systemd 服务,请执行 'systemctl list-unit-files'。
查看在具体 target 启用的服务请执行
'systemctl list-dependencies [target]'。
mysqld 0:关 1:关 2:关 3:关 4:关 5:关 6:关
netconsole 0:关 1:关 2:关 3:关 4:关 5:关 6:关
network 0:关 1:关 2:开 3:开 4:开 5:开 6:关
某服务开机启动:(针对2345级别,因为016级别开机启动没意义)
[root@lgs ~]# chkconfig mysqld on
[root@lgs ~]# chkconfig --list
注:该输出结果只显示 SysV 服务,并不包含
原生 systemd 服务。SysV 配置数据
可能被原生 systemd 配置覆盖。
要列出 systemd 服务,请执行 'systemctl list-unit-files'。
查看在具体 target 启用的服务请执行
'systemctl list-dependencies [target]'。
mysqld 0:关 1:关 2:开 3:开 4:开 5:开 6:关
netconsole 0:关 1:关 2:关 3:关 4:关 5:关 6:关
network 0:关 1:关 2:开 3:开 4:开 5:开 6:关
指定级别开机启动或关闭:
[root@lgs ~]# chkconfig --level 45 mysqld off
[root@lgs ~]# chkconfig --list
注:该输出结果只显示 SysV 服务,并不包含
原生 systemd 服务。SysV 配置数据
可能被原生 systemd 配置覆盖。
要列出 systemd 服务,请执行 'systemctl list-unit-files'。
查看在具体 target 启用的服务请执行
'systemctl list-dependencies [target]'。
mysqld 0:关 1:关 2:开 3:开 4:关 5:关 6:关
netconsole 0:关 1:关 2:关 3:关 4:关 5:关 6:关
network 0:关 1:关 2:开 3:开 4:开 5:开 6:关
要把用户自定义(自己安装的)服务加入chkconfig列表去管理:chkconfig --add
(服务的文件必须在/etc/init.d/ 下)
[root@lgs ~]# chkconfig --add 123
服务 123 信息读取出错:没有那个文件或目录
[root@lgs ~]# cd /etc/init.d/
[root@lgs init.d]# ls
functions httpd mysqld netconsole network README
[root@lgs init.d]# cp network 123
[root@lgs init.d]# chkconfig --add 123
[root@lgs init.d]# chkconfig --list
注:该输出结果只显示 SysV 服务,并不包含
原生 systemd 服务。SysV 配置数据
可能被原生 systemd 配置覆盖。
要列出 systemd 服务,请执行 'systemctl list-unit-files'。
查看在具体 target 启用的服务请执行
'systemctl list-dependencies [target]'。
123 0:关 1:关 2:开 3:开 4:开 5:开 6:关
mysqld 0:关 1:关 2:开 3:开 4:关 5:关 6:关
netconsole 0:关 1:关 2:关 3:关 4:关 5:关 6:关
network 0:关 1:关 2:开 3:开 4:开 5:开 6:关
123脚本或者服务要被chkconfig识别,必须在脚本里编写以下参数
chkconfig: 2345 10 90:2345运行级别启动、10位启动、90位关闭。
[root@lgs init.d]# cat 123
# chkconfig: 2345 10 90
# description: Activates/Deactivates all network interfaces configured to \
# start at boot time.
删除列表中的服务:
[root@lgs init.d]# chkconfig --del 123
[root@lgs init.d]# chkconfig --list
注:该输出结果只显示 SysV 服务,并不包含
原生 systemd 服务。SysV 配置数据
可能被原生 systemd 配置覆盖。
要列出 systemd 服务,请执行 'systemctl list-unit-files'。
查看在具体 target 启用的服务请执行
'systemctl list-dependencies [target]'。
mysqld 0:关 1:关 2:开 3:开 4:关 5:关 6:关
netconsole 0:关 1:关 2:关 3:关 4:关 5:关 6:关
network 0:关 1:关 2:开 3:开 4:开 5:开 6:关
10.25 systemd管理服务
在CentOS7中, 主要用systemd管理服务,chkconfig已经很少使用。
查看所有服务:service、target、socket等类型。
[root@lgs ~]# systemctl list-unit-files
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
tmp.mount disabled
brandbot.path disabled
systemd-ask-password-console.path static
systemd-ask-password-plymouth.path static
systemd-ask-password-wall.path static
session-2.scope static
session-4.scope static
accounts-daemon.service enabled
arp-ethers.service disabled
auditd.service enabled
[email protected] enabled
blk-availability.service disabled
bluetooth.service enabled
brandbot.service static
canberra-system-bootup.service disabled
canberra-system-shutdown-reboot.service disabled
canberra-system-shutdown.service disabled
[email protected] static
chrony-wait.service disabled
chronyd.service enabled
colord.service static
console-getty.service disabled
console-shell.service disabled
[email protected] static
cpupower.service disabled
crond.service enabled
dbus-org.bluez.service enabled
dbus-org.freedesktop.hostname1.service static
dbus-org.freedesktop.import1.service static
dbus-org.freedesktop.locale1.service static
dbus-org.freedesktop.login1.service static
dbus-org.freedesktop.machine1.service static
dbus-org.freedesktop.NetworkManager.service enabled
dbus-org.freedesktop.nm-dispatcher.service enabled
dbus-org.freedesktop.timedate1.service static
dbus.service static
debug-shell.service disabled
display-manager.service enabled
dm-event.service disabled
dracut-cmdline.service static
dracut-initqueue.service static
dracut-mount.service static
dracut-pre-mount.service static
dracut-pre-pivot.service static
dracut-pre-trigger.service static
dracut-pre-udev.service static
dracut-shutdown.service static
ebtables.service disabled
emergency.service static
firewalld.service disabled
fstrim.service static
gdm.service enabled
geoclue.service static
[email protected] enabled
halt-local.service static
initrd-cleanup.service static
initrd-parse-etc.service static
initrd-switch-root.service static
initrd-udevadm-cleanup-db.service static
ip6tables.service disabled
iprdump.service disabled
iprinit.service disabled
iprupdate.service disabled
iptables.service enabled
irqbalance.service enabled
kdump.service enabled
kmod-static-nodes.service static
lvm2-lvmetad.service disabled
lvm2-lvmpolld.service disabled
lvm2-monitor.service enabled
[email protected] static
messagebus.service static
microcode.service enabled
NetworkManager-dispatcher.service enabled
NetworkManager-wait-online.service disabled
NetworkManager.service enabled
oddjobd.service disabled
plymouth-halt.service disabled
plymouth-kexec.service disabled
plymouth-poweroff.service disabled
plymouth-quit-wait.service disabled
plymouth-quit.service disabled
plymouth-read-write.service disabled
plymouth-reboot.service disabled
plymouth-start.service disabled
plymouth-switch-root.service static
polkit.service static
postfix.service enabled
quotaon.service static
rc-local.service static
rdisc.service disabled
realmd.service static
rescue.service static
rhel-autorelabel-mark.service static
rhel-autorelabel.service static
rhel-configure.service static
rhel-dmesg.service disabled
rhel-domainname.service disabled
rhel-import-state.service static
rhel-loadmodules.service static
rhel-readonly.service static
rsyslog.service enabled
rtkit-daemon.service enabled
[email protected] static
[email protected] disabled
sshd-keygen.service static
sshd.service enabled
[email protected] static
sysstat.service enabled
systemd-ask-password-console.service static
systemd-ask-password-plymouth.service static
systemd-ask-password-wall.service static
[email protected] static
systemd-binfmt.service static
systemd-bootchart.service disabled
systemd-firstboot.service static
systemd-fsck-root.service static
[email protected] static
systemd-halt.service static
[email protected] static
systemd-hibernate.service static
systemd-hostnamed.service static
systemd-hwdb-update.service static
systemd-hybrid-sleep.service static
systemd-importd.service static
systemd-initctl.service static
systemd-journal-catalog-update.service static
systemd-journal-flush.service static
systemd-journald.service static
systemd-kexec.service static
systemd-localed.service static
systemd-logind.service static
systemd-machine-id-commit.service static
systemd-machined.service static
systemd-modules-load.service static
[email protected] disabled
systemd-poweroff.service static
systemd-quotacheck.service static
systemd-random-seed.service static
systemd-readahead-collect.service enabled
systemd-readahead-done.service indirect
systemd-readahead-drop.service enabled
systemd-readahead-replay.service enabled
systemd-reboot.service static
systemd-remount-fs.service static
[email protected] static
systemd-shutdownd.service static
systemd-suspend.service static
systemd-sysctl.service static
systemd-timedated.service static
systemd-tmpfiles-clean.service static
systemd-tmpfiles-setup-dev.service static
systemd-tmpfiles-setup.service static
systemd-udev-settle.service static
systemd-udev-trigger.service static
systemd-udevd.service static
systemd-update-done.service static
systemd-update-utmp-runlevel.service static
systemd-update-utmp.service static
systemd-user-sessions.service static
systemd-vconsole-setup.service static
tcsd.service disabled
[email protected] static
tuned.service enabled
upower.service disabled
vgauthd.service enabled
vmtoolsd.service enabled
wpa_supplicant.service disabled
-.slice static
machine.slice static
system.slice static
user-0.slice static
user.slice static
dbus.socket static
dm-event.socket enabled
lvm2-lvmetad.socket enabled
lvm2-lvmpolld.socket enabled
sshd.socket disabled
syslog.socket static
systemd-initctl.socket static
systemd-journald.socket static
systemd-shutdownd.socket static
systemd-udevd-control.socket static
systemd-udevd-kernel.socket static
basic.target static
bluetooth.target static
cryptsetup-pre.target static
cryptsetup.target static
ctrl-alt-del.target disabled
default.target enabled
emergency.target static
final.target static
getty.target static
graphical.target static
halt.target disabled
hibernate.target static
hybrid-sleep.target static
initrd-fs.target static
initrd-root-fs.target static
initrd-switch-root.target static
initrd.target static
iprutils.target disabled
kexec.target disabled
local-fs-pre.target static
local-fs.target static
machines.target disabled
multi-user.target enabled
network-online.target static
network-pre.target static
network.target static
nss-lookup.target static
nss-user-lookup.target static
paths.target static
poweroff.target disabled
printer.target static
reboot.target disabled
remote-fs-pre.target static
remote-fs.target enabled
rescue.target disabled
rpcbind.target static
runlevel0.target disabled
runlevel1.target disabled
runlevel2.target enabled
runlevel3.target enabled
runlevel4.target enabled
runlevel5.target static
runlevel6.target disabled
shutdown.target static
sigpwr.target static
sleep.target static
slices.target static
smartcard.target static
sockets.target static
sound.target static
suspend.target static
swap.target static
sysinit.target static
system-update.target static
time-sync.target static
timers.target static
umount.target static
[email protected] disabled
fstrim.timer disabled
systemd-readahead-done.timer indirect
systemd-tmpfiles-clean.timer static
252 unit files listed.
lines 210-255/255 (END)
指定类型list:
[root@lgs ~]# systemctl list-units --type=service
UNIT LOAD ACTIVE SUB DESCRIPTION
auditd.service loaded active running Security Auditing Service
chronyd.service loaded active running NTP client/server
crond.service loaded active running Command Scheduler
dbus.service loaded active running D-Bus System Message Bus
[email protected] loaded active running Getty on tty1
iptables.service loaded active exited IPv4 firewall with iptables
irqbalance.service loaded active running irqbalance daemon
kdump.service loaded active exited Crash recovery kernel arming
kmod-static-nodes.service loaded active exited Create list of required static device nodes for the current kernel
lvm2-lvmetad.service loaded active running LVM2 metadata daemon
lvm2-monitor.service loaded active exited Monitoring of LVM2 mirrors, snapshots etc. using dmeventd or progress polling
lvm2-pvscan@8:17.service loaded active exited LVM2 PV scan on device 8:17
lvm2-pvscan@8:18.service loaded active exited LVM2 PV scan on device 8:18
lvm2-pvscan@8:19.service loaded active exited LVM2 PV scan on device 8:19
mysqld.service loaded active running LSB: start and stop MySQL
network.service loaded active exited LSB: Bring up/down networking
NetworkManager-wait-online.service loaded active exited Network Manager Wait Online
NetworkManager.service loaded active running Network Manager
polkit.service loaded active running Authorization Manager
postfix.service loaded active running Postfix Mail Transport Agent
● rc-local.service loaded failed failed /etc/rc.d/rc.local Compatibility
rhel-autorelabel-mark.service loaded active exited Mark the need to relabel after reboot
rhel-dmesg.service loaded active exited Dump dmesg to /var/log/dmesg
--all选项:显示所有的service(包括active激活的和inactive未激活的)
[root@lgs ~]# systemctl list-units --all --type=service
UNIT LOAD ACTIVE SUB DESCRIPTION
accounts-daemon.service loaded inactive dead Accounts Service
auditd.service loaded active running Security Auditing Service
brandbot.service loaded inactive dead Flexible Branding Service
chronyd.service loaded active running NTP client/server
cpupower.service loaded inactive dead Configure CPU power related settings
crond.service loaded active running Command Scheduler
dbus.service loaded active running D-Bus System Message Bus
dm-event.service loaded inactive dead Device-mapper event daemon
dracut-shutdown.service loaded inactive dead Restore /run/initramfs
emergency.service loaded inactive dead Emergency Shell
● exim.service not-found inactive dead exim.service
gdm.service loaded inactive dead GNOME Display Manager
[email protected] loaded active running Getty on tty1
ip6tables.service loaded inactive dead IPv6 firewall with ip6tables
iptables.service loaded active exited IPv4 firewall with iptables
irqbalance.service loaded active running irqbalance daemon
kdump.service loaded active exited Crash recovery kernel arming
kmod-static-nodes.service loaded active exited Create list of required static device nodes for the current kernel
● ldap.service not-found inactive dead ldap.service
● lvm2-activation.service not-found inactive dead lvm2-activation.service
开机启动:.service可以不写。
[root@lgs ~]# systemctl enable crond.service
检查是否开机启动:
[root@lgs ~]# systemctl is-enabled crond
enabled
开机不启动:
[root@lgs ~]# systemctl disable crond.service
Removed symlink /etc/systemd/system/multi-user.target.wants/crond.service.
[root@lgs ~]# systemctl is-enabled crond
disabled
查看服务状态:
[root@lgs ~]# systemctl status crond
● crond.service - Command Scheduler
Loaded: loaded (/usr/lib/systemd/system/crond.service; disabled; vendor preset: enabled)
Active: active (running) since 日 2018-05-13 11:47:51 CST; 49min ago
Main PID: 572 (crond)
CGroup: /system.slice/crond.service
└─572 /usr/sbin/crond -n
5月 13 11:47:51 lgs systemd[1]: Started Command Scheduler.
5月 13 11:47:51 lgs systemd[1]: Starting Command Scheduler...
5月 13 11:47:51 lgs crond[572]: (CRON) INFO (RANDOM_DELAY will be scaled with factor 74% if used.)
5月 13 11:47:51 lgs crond[572]: (CRON) INFO (running with inotify support)
单独开启、停止、重启服务:
[root@lgs ~]# systemctl stop crond
[root@lgs ~]# systemctl start crond
[root@lgs ~]# systemctl restart crond
如果一个服务设置开机启动后,会生成一个软链接文件:
如果设置开机不启动后,软链接文件就会被删除。
[root@lgs ~]# systemctl enable crond
Created symlink from /etc/systemd/system/multi-user.target.wants/crond.service to /usr/lib/systemd/system/crond.service.
[root@lgs ~]# ls -l /etc/systemd/system/multi-user.target.wants/crond.service
lrwxrwxrwx 1 root root 37 5月 13 12:40 /etc/systemd/system/multi-user.target.wants/crond.service -> /usr/lib/systemd/system/crond.service
[root@lgs ~]# systemctl disable crond
Removed symlink /etc/systemd/system/multi-user.target.wants/crond.service.
[root@lgs ~]# ls -l /etc/systemd/system/multi-user.target.wants/crond.service
ls: 无法访问/etc/systemd/system/multi-user.target.wants/crond.service: 没有那个文件或目录
10.26 unit介绍
systemd开启和监督整个系统是基于unit的概念。unit是由一个与配置文件名同名的名字和类型组成的一个封装单元。
unit有很多类型: service:系统服务; target:多个unit组成的组; device:硬件设备;
mount:文件系统的挂载点; automount:自动挂载点; path:文件或者路径
scope:不是由systemd启动的外部进程; slice:进程组; snapshot:systemd 快照
socket:进程间通信的套接字; swap:swap文件; timer:定时器。
列出正在运行的unit:
[root@lgs ~]# systemctl list-units
UNIT LOAD ACTIVE SUB DESCRIPTION
proc-sys-fs-binfmt_misc.automount loaded active waiting Arbitrary Executable File Formats File System Automount Point
sys-devices-pci0000:00-0000:00:07.1-ata2-host1-target1:0:0-1:0:0:0-block-sr0.device loaded active plugged VMware_Virtual_IDE_CDROM_Drive
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:0-2:0:0:0-block-sda-sda1.device loaded active plugged VMware_Virtual_S 1
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:0-2:0:0:0-block-sda-sda2.device loaded active plugged VMware_Virtual_S 2
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:0-2:0:0:0-block-sda-sda3.device loaded active plugged VMware_Virtual_S 3
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:0-2:0:0:0-block-sda.device loaded active plugged VMware_Virtual_S
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:1-2:0:1:0-block-sdb-sdb1.device loaded active plugged LVM PV m8V6a8-xkMn-W5tX-YAIQ-30Xz-dqNz-TvZ6yS on
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:1-2:0:1:0-block-sdb-sdb2.device loaded active plugged LVM PV EoP8W8-B3x1-V2FW-kyY9-dHhy-6eIh-StZvVB on
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:1-2:0:1:0-block-sdb-sdb3.device loaded active plugged LVM PV DrJCcW-NoZ3-1zUk-u3OE-PdET-rLAb-eyXCyd on
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:1-2:0:1:0-block-sdb.device loaded active plugged VMware_Virtual_S
sys-devices-pci0000:00-0000:00:11.0-0000:02:01.0-net-ens33.device loaded active plugged 82545EM Gigabit Ethernet Controller (Copper) (PRO/1000 MT Single P
sys-devices-pci0000:00-0000:00:11.0-0000:02:02.0-sound-card0.device loaded active plugged ES1371/ES1373 / Creative Labs CT2518 (Audio PCI 64V/128/5200 / C
sys-devices-platform-serial8250-tty-ttyS1.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS1
sys-devices-platform-serial8250-tty-ttyS2.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS2
sys-devices-platform-serial8250-tty-ttyS3.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS3
sys-devices-pnp0-00:05-tty-ttyS0.device loaded active plugged /sys/devices/pnp0/00:05/tty/ttyS0
sys-devices-virtual-block-dm\x2d0.device loaded active plugged /sys/devices/virtual/block/dm-0
sys-module-configfs.device loaded active plugged /sys/module/configfs
sys-subsystem-net-devices-ens33.device loaded active plugged 82545EM Gigabit Ethernet Controller (Copper) (PRO/1000 MT Single P
-.mount loaded active mounted /
boot.mount loaded active mounted /boot
dev-hugepages.mount loaded active mounted Huge Pages File System
dev-mqueue.mount loaded active mounted POSIX Message Queue File System
run-user-0.mount loaded active mounted /run/user/0
sys-kernel-config.mount loaded active mounted Configuration File System
sys-kernel-debug.mount loaded active mounted Debug File System
brandbot.path loaded active waiting Flexible branding
systemd-ask-password-plymouth.path loaded active waiting Forward Password Requests to Plymouth Directory Watch
systemd-ask-password-wall.path loaded active waiting Forward Password Requests to Wall Directory Watch
session-2.scope loaded active running Session 2 of user root
auditd.service loaded active running Security Auditing Service
chronyd.service loaded active running NTP client/server
crond.service loaded active running Command Scheduler
dbus.service loaded active running D-Bus System Message Bus
[email protected] loaded active running Getty on tty1
iptables.service loaded active exited IPv4 firewall with iptables
irqbalance.service loaded active running irqbalance daemon
kdump.service loaded active exited Crash recovery kernel arming
kmod-static-nodes.service loaded active exited Create list of required static device nodes for the current kernel
lvm2-lvmetad.service loaded active running LVM2 metadata daemon
lvm2-monitor.service loaded active exited Monitoring of LVM2 mirrors, snapshots etc. using dmeventd or progr
lvm2-pvscan@8:17.service loaded active exited LVM2 PV scan on device 8:17
lvm2-pvscan@8:18.service loaded active exited LVM2 PV scan on device 8:18
lvm2-pvscan@8:19.service loaded active exited LVM2 PV scan on device 8:19
mysqld.service loaded active running LSB: start and stop MySQL
network.service loaded active exited LSB: Bring up/down networking
NetworkManager-wait-online.service loaded active exited Network Manager Wait Online
NetworkManager.service loaded active running Network Manager
polkit.service loaded active running Authorization Manager
postfix.service loaded active running Postfix Mail Transport Agent
● rc-local.service loaded failed failed /etc/rc.d/rc.local Compatibility
rhel-autorelabel-mark.service loaded active exited Mark the need to relabel after reboot
rhel-dmesg.service loaded active exited Dump dmesg to /var/log/dmesg
rhel-import-state.service loaded active exited Import network configuration from initramfs
rhel-readonly.service loaded active exited Configure read-only root support
rsyslog.service loaded active running System Logging Service
sshd.service loaded active running OpenSSH server daemon
sysstat.service loaded active exited Resets System Activity Logs
systemd-journal-flush.service loaded active exited Flush Journal to Persistent Storage
systemd-journald.service loaded active running Journal Service
systemd-logind.service loaded active running Login Service
systemd-random-seed.service loaded active exited Load/Save Random Seed
systemd-remount-fs.service loaded active exited Remount Root and Kernel File Systems
systemd-sysctl.service loaded active exited Apply Kernel Variables
systemd-tmpfiles-setup-dev.service loaded active exited Create Static Device Nodes in /dev
systemd-tmpfiles-setup.service loaded active exited Create Volatile Files and Directories
systemd-udev-trigger.service loaded active exited udev Coldplug all Devices
systemd-udevd.service loaded active running udev Kernel Device Manager
systemd-update-utmp.service loaded active exited Update UTMP about System Boot/Shutdown
systemd-user-sessions.service loaded active exited Permit User Sessions
systemd-vconsole-setup.service loaded active exited Setup Virtual Console
tuned.service loaded active running Dynamic System Tuning Daemon
vgauthd.service loaded active running VGAuth Service for open-vm-tools
vmtoolsd.service loaded active running Service for virtual machines hosted on VMware
-.slice loaded active active Root Slice
system-getty.slice loaded active active system-getty.slice
system-lvm2\x2dpvscan.slice loaded active active system-lvm2\x2dpvscan.slice
system-selinux\x2dpolicy\x2dmigrate\x2dlocal\x2dchanges.slice loaded active active system-selinux\x2dpolicy\x2dmigrate\x2dlocal\x2dchanges.slice
system.slice loaded active active System Slice
user-0.slice loaded active active User Slice of root
user.slice loaded active active User and Session Slice
dbus.socket loaded active running D-Bus System Message Bus Socket
dm-event.socket loaded active listening Device-mapper event daemon FIFOs
lvm2-lvmetad.socket loaded active running LVM2 metadata daemon socket
lvm2-lvmpolld.socket loaded active listening LVM2 poll daemon socket
systemd-initctl.socket loaded active listening /dev/initctl Compatibility Named Pipe
systemd-journald.socket loaded active running Journal Socket
systemd-shutdownd.socket loaded active listening Delayed Shutdown Socket
systemd-udevd-control.socket loaded active running udev Control Socket
systemd-udevd-kernel.socket loaded active running udev Kernel Socket
dev-disk-by\x2duuid-deb5a799\x2d817e\x2d41a2\x2d8ab5\x2d25893d3247b2.swap loaded active active /dev/disk/by-uuid/deb5a799-817e-41a2-8ab5-25893d3247b2
basic.target loaded active active Basic System
cryptsetup.target loaded active active Encrypted Volumes
getty.target loaded active active Login Prompts
local-fs-pre.target loaded active active Local File Systems (Pre)
local-fs.target loaded active active Local File Systems
multi-user.target loaded active active Multi-User System
network-online.target loaded active active Network is Online
network.target loaded active active Network
paths.target loaded active active Paths
remote-fs.target loaded active active Remote File Systems
slices.target loaded active active Slices
sockets.target loaded active active Sockets
sound.target loaded active active Sound Card
swap.target loaded active active Swap
sysinit.target loaded active active System Initialization
timers.target loaded active active Timers
systemd-tmpfiles-clean.timer loaded active waiting Daily Cleanup of Temporary Directories
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.
108 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.
lines 71-116/116 (END)
--all选项:列出所有的units,包括inactive、和失败的。
[root@lgs ~]# systemctl list-units --all
UNIT LOAD ACTIVE SUB DESCRIPTION
proc-sys-fs-binfmt_misc.automount loaded active waiting Arbitrary Executable File Formats File System Automount Point
dev-block-8:17.device loaded active plugged LVM PV m8V6a8-xkMn-W5tX-YAIQ-30Xz-dqNz-TvZ6yS on /dev/sdb1 1
dev-block-8:18.device loaded active plugged LVM PV EoP8W8-B3x1-V2FW-kyY9-dHhy-6eIh-StZvVB on /dev/sdb2 2
dev-block-8:19.device loaded active plugged LVM PV DrJCcW-NoZ3-1zUk-u3OE-PdET-rLAb-eyXCyd on /dev/sdb3 3
dev-cdrom.device loaded active plugged VMware_Virtual_IDE_CDROM_Drive
dev-disk-by\x2did-ata\x2dVMware_Virtual_IDE_CDROM_Drive_10000000000000000001.device loaded active plugged VMware_Virtual_IDE_CDROM_Drive
dev-disk-by\x2did-dm\x2dname\x2dvg1\x2dlv1.device loaded active plugged /dev/disk/by-id/dm-name-vg1-lv1
dev-disk-by\x2did-dm\x2duuid\x2dLVM\x2d52fM6w9Z59cxCGS41hhRqVi76fnUmE3jJmFXe58h09mT5xXh1oFbU3dmL7OH1mU9.device loaded active plugged /dev/disk/by-id/
dev-disk-by\x2did-lvm\x2dpv\x2duuid\x2dDrJCcW\x2dNoZ3\x2d1zUk\x2du3OE\x2dPdET\x2drLAb\x2deyXCyd.device loaded active plugged LVM PV DrJCcW-NoZ3-1zUk-
dev-disk-by\x2did-lvm\x2dpv\x2duuid\x2dEoP8W8\x2dB3x1\x2dV2FW\x2dkyY9\x2ddHhy\x2d6eIh\x2dStZvVB.device loaded active plugged LVM PV EoP8W8-B3x1-V2FW-
dev-disk-by\x2did-lvm\x2dpv\x2duuid\x2dm8V6a8\x2dxkMn\x2dW5tX\x2dYAIQ\x2d30Xz\x2ddqNz\x2dTvZ6yS.device loaded active plugged LVM PV m8V6a8-xkMn-W5tX-
dev-disk-by\x2dpath-pci\x2d0000:00:07.1\x2data\x2d2.0.device loaded active plugged VMware_Virtual_IDE_CDROM_Drive
dev-disk-by\x2dpath-pci\x2d0000:00:10.0\x2dscsi\x2d0:0:0:0.device loaded active plugged VMware_Virtual_S
dev-disk-by\x2dpath-pci\x2d0000:00:10.0\x2dscsi\x2d0:0:0:0\x2dpart1.device loaded active plugged VMware_Virtual_S 1
dev-disk-by\x2dpath-pci\x2d0000:00:10.0\x2dscsi\x2d0:0:0:0\x2dpart2.device loaded active plugged VMware_Virtual_S 2
dev-disk-by\x2dpath-pci\x2d0000:00:10.0\x2dscsi\x2d0:0:0:0\x2dpart3.device loaded active plugged VMware_Virtual_S 3
dev-disk-by\x2dpath-pci\x2d0000:00:10.0\x2dscsi\x2d0:0:1:0.device loaded active plugged VMware_Virtual_S
dev-disk-by\x2dpath-pci\x2d0000:00:10.0\x2dscsi\x2d0:0:1:0\x2dpart1.device loaded active plugged LVM PV m8V6a8-xkMn-W5tX-YAIQ-30Xz-dqNz-TvZ6yS on /de
dev-disk-by\x2dpath-pci\x2d0000:00:10.0\x2dscsi\x2d0:0:1:0\x2dpart2.device loaded active plugged LVM PV EoP8W8-B3x1-V2FW-kyY9-dHhy-6eIh-StZvVB on /de
dev-disk-by\x2dpath-pci\x2d0000:00:10.0\x2dscsi\x2d0:0:1:0\x2dpart3.device loaded active plugged LVM PV DrJCcW-NoZ3-1zUk-u3OE-PdET-rLAb-eyXCyd on /de
dev-disk-by\x2duuid-02635225\x2ddce3\x2d410a\x2d932d\x2d9e6d38fc22f3.device loaded active plugged /dev/disk/by-uuid/02635225-dce3-410a-932d-9e6d38fc2
dev-disk-by\x2duuid-9fa2450c\x2d5b1c\x2d4cd6\x2d99a0\x2d8c6baa0dc6f5.device loaded active plugged VMware_Virtual_S 1
dev-disk-by\x2duuid-deb5a799\x2d817e\x2d41a2\x2d8ab5\x2d25893d3247b2.device loaded active plugged VMware_Virtual_S 2
dev-disk-by\x2duuid-fefaab3f\x2d8726\x2d4a25\x2d9e55\x2dcea60b974233.device loaded active plugged VMware_Virtual_S 3
dev-dm\x2d0.device loaded active plugged /dev/dm-0
dev-mapper-vg1\x2dlv1.device loaded active plugged /dev/mapper/vg1-lv1
dev-sda.device loaded active plugged VMware_Virtual_S
dev-sda1.device loaded active plugged VMware_Virtual_S 1
dev-sda2.device loaded active plugged VMware_Virtual_S 2
dev-sda3.device loaded active plugged VMware_Virtual_S 3
dev-sdb.device loaded active plugged VMware_Virtual_S
dev-sdb1.device loaded active plugged LVM PV m8V6a8-xkMn-W5tX-YAIQ-30Xz-dqNz-TvZ6yS on /dev/sdb1 1
dev-sdb2.device loaded active plugged LVM PV EoP8W8-B3x1-V2FW-kyY9-dHhy-6eIh-StZvVB on /dev/sdb2 2
dev-sdb3.device loaded active plugged LVM PV DrJCcW-NoZ3-1zUk-u3OE-PdET-rLAb-eyXCyd on /dev/sdb3 3
dev-sr0.device loaded active plugged VMware_Virtual_IDE_CDROM_Drive
dev-ttyS0.device loaded active plugged /dev/ttyS0
dev-ttyS1.device loaded active plugged /dev/ttyS1
dev-ttyS2.device loaded active plugged /dev/ttyS2
dev-ttyS3.device loaded active plugged /dev/ttyS3
dev-vg1-lv1.device loaded active plugged /dev/vg1/lv1
sys-devices-pci0000:00-0000:00:07.1-ata2-host1-target1:0:0-1:0:0:0-block-sr0.device loaded active plugged VMware_Virtual_IDE_CDROM_Drive
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:0-2:0:0:0-block-sda-sda1.device loaded active plugged VMware_Virtual_S 1
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:0-2:0:0:0-block-sda-sda2.device loaded active plugged VMware_Virtual_S 2
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:0-2:0:0:0-block-sda-sda3.device loaded active plugged VMware_Virtual_S 3
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:0-2:0:0:0-block-sda.device loaded active plugged VMware_Virtual_S
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:1-2:0:1:0-block-sdb-sdb1.device loaded active plugged LVM PV m8V6a8-xkMn-W5tX-YAIQ-30Xz-dqNz-TvZ6
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:1-2:0:1:0-block-sdb-sdb2.device loaded active plugged LVM PV EoP8W8-B3x1-V2FW-kyY9-dHhy-6eIh-StZv
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:1-2:0:1:0-block-sdb-sdb3.device loaded active plugged LVM PV DrJCcW-NoZ3-1zUk-u3OE-PdET-rLAb-eyXC
sys-devices-pci0000:00-0000:00:10.0-host2-target2:0:1-2:0:1:0-block-sdb.device loaded active plugged VMware_Virtual_S
sys-devices-pci0000:00-0000:00:11.0-0000:02:01.0-net-ens33.device loaded active plugged 82545EM Gigabit Ethernet Controller (Copper) (PRO/1000 MT Sin
sys-devices-pci0000:00-0000:00:11.0-0000:02:02.0-sound-card0.device loaded active plugged ES1371/ES1373 / Creative Labs CT2518 (Audio PCI 64V/128/520
sys-devices-platform-serial8250-tty-ttyS1.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS1
sys-devices-platform-serial8250-tty-ttyS2.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS2
sys-devices-platform-serial8250-tty-ttyS3.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS3
sys-devices-pnp0-00:05-tty-ttyS0.device loaded active plugged /sys/devices/pnp0/00:05/tty/ttyS0
sys-devices-virtual-block-dm\x2d0.device loaded active plugged /sys/devices/virtual/block/dm-0
sys-module-configfs.device loaded active plugged /sys/module/configfs
sys-subsystem-net-devices-ens33.device loaded active plugged 82545EM Gigabit Ethernet Controller (Copper) (PRO/1000 MT Sing
-.mount loaded active mounted /
boot.mount loaded active mounted /boot
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 inactive dead Arbitrary Executable File Formats File System
run-user-0.mount loaded active mounted /run/user/0
sys-fs-fuse-connections.mount loaded inactive dead FUSE Control File System
sys-kernel-config.mount loaded active mounted Configuration File System
sys-kernel-debug.mount loaded active mounted Debug File System
tmp.mount loaded inactive dead Temporary Directory
brandbot.path loaded active waiting Flexible branding
systemd-ask-password-console.path loaded inactive dead Dispatch Password Requests to Console Directory Watch
systemd-ask-password-plymouth.path loaded active waiting Forward Password Requests to Plymouth Directory Watch
systemd-ask-password-wall.path loaded active waiting Forward Password Requests to Wall Directory Watch
session-2.scope loaded active running Session 2 of user root
accounts-daemon.service loaded inactive dead Accounts Service
auditd.service loaded active running Security Auditing Service
brandbot.service loaded inactive dead Flexible Branding Service
chronyd.service loaded active running NTP client/server
cpupower.service loaded inactive dead Configure CPU power related settings
crond.service loaded active running Command Scheduler
dbus.service loaded active running D-Bus System Message Bus
dm-event.service loaded inactive dead Device-mapper event daemon
dracut-shutdown.service loaded inactive dead Restore /run/initramfs
emergency.service loaded inactive dead Emergency Shell
● exim.service not-found inactive dead exim.service
gdm.service loaded inactive dead GNOME Display Manager
[email protected] loaded active running Getty on tty1
ip6tables.service loaded inactive dead IPv6 firewall with ip6tables
iptables.service loaded active exited IPv4 firewall with iptables
irqbalance.service loaded active running irqbalance daemon
kdump.service loaded active exited Crash recovery kernel arming
kmod-static-nodes.service loaded active exited Create list of required static device nodes for the current ke
● ldap.service not-found inactive dead ldap.service
● lvm2-activation.service not-found inactive dead lvm2-activation.service
lvm2-lvmetad.service loaded active running LVM2 metadata daemon
lvm2-lvmpolld.service loaded inactive dead LVM2 poll daemon
lvm2-monitor.service loaded active exited Monitoring of LVM2 mirrors, snapshots etc. using dmeventd or p
lvm2-pvscan@8:17.service loaded active exited LVM2 PV scan on device 8:17
lvm2-pvscan@8:18.service loaded active exited LVM2 PV scan on device 8:18
lvm2-pvscan@8:19.service loaded active exited LVM2 PV scan on device 8:19
microcode.service loaded inactive dead Load CPU microcode update
mysqld.service loaded active running LSB: start and stop MySQL
network.service loaded active exited LSB: Bring up/down networking
NetworkManager-wait-online.service loaded active exited Network Manager Wait Online
NetworkManager.service loaded active running Network Manager
● nscd.service not-found inactive dead nscd.service
● ntpd.service not-found inactive dead ntpd.service
● ntpdate.service not-found inactive dead ntpdate.service
plymouth-quit-wait.service loaded inactive dead Wait for Plymouth Boot Screen to Quit
plymouth-quit.service loaded inactive dead Terminate Plymouth Boot Screen
plymouth-read-write.service loaded inactive dead Tell Plymouth To Write Out Runtime Data
plymouth-start.service loaded inactive dead Show Plymouth Boot Screen
polkit.service loaded active running Authorization Manager
postfix.service loaded active running Postfix Mail Transport Agent
● rc-local.service loaded failed failed /etc/rc.d/rc.local Compatibility
--state选项:指定状态
[root@lgs ~]# systemctl list-units --all --state=inactive
UNIT LOAD ACTIVE SUB DESCRIPTION
proc-sys-fs-binfmt_misc.mount loaded inactive dead Arbitrary Executable File Formats File System
sys-fs-fuse-connections.mount loaded inactive dead FUSE Control File System
tmp.mount loaded inactive dead Temporary Directory
systemd-ask-password-console.path loaded inactive dead Dispatch Password Requests to Console Directory Watch
accounts-daemon.service loaded inactive dead Accounts Service
brandbot.service loaded inactive dead Flexible Branding Service
cpupower.service loaded inactive dead Configure CPU power related settings
dm-event.service loaded inactive dead Device-mapper event daemon
dracut-shutdown.service loaded inactive dead Restore /run/initramfs
emergency.service loaded inactive dead Emergency Shell
● exim.service not-found inactive dead exim.service
gdm.service loaded inactive dead GNOME Display Manager
ip6tables.service loaded inactive dead IPv6 firewall with ip6tables
● ldap.service not-found inactive dead ldap.service
● lvm2-activation.service not-found inactive dead lvm2-activation.service
lvm2-lvmpolld.service loaded inactive dead LVM2 poll daemon
microcode.service loaded inactive dead Load CPU microcode update
--type选项:指定类型
[root@lgs ~]# systemctl list-units --all --type=service
UNIT LOAD ACTIVE SUB DESCRIPTION
accounts-daemon.service loaded inactive dead Accounts Service
auditd.service loaded active running Security Auditing Service
brandbot.service loaded inactive dead Flexible Branding Service
chronyd.service loaded active running NTP client/server
cpupower.service loaded inactive dead Configure CPU power related settings
crond.service loaded active running Command Scheduler
dbus.service loaded active running D-Bus System Message Bus
dm-event.service loaded inactive dead Device-mapper event daemon
dracut-shutdown.service loaded inactive dead Restore /run/initramfs
emergency.service loaded inactive dead Emergency Shell
● exim.service not-found inactive dead exim.service
gdm.service loaded inactive dead GNOME Display Manager
[email protected] loaded active running Getty on tty1
查看指定服务是否激活:
[root@lgs ~]# systemctl is-active crond
active
10.27 target介绍
系统为了方便管理,用target来管理units
列出系统的target:
[root@lgs ~]# systemctl list-unit-files --type=target
UNIT FILE STATE
basic.target static
bluetooth.target static
cryptsetup-pre.target static
cryptsetup.target static
ctrl-alt-del.target disabled
default.target enabled
emergency.target static
final.target static
getty.target static
graphical.target static
halt.target disabled
hibernate.target static
hybrid-sleep.target static
initrd-fs.target static
initrd-root-fs.target static
initrd-switch-root.target static
initrd.target static
iprutils.target disabled
kexec.target disabled
local-fs-pre.target static
local-fs.target static
machines.target disabled
multi-user.target enabled
network-online.target static
network-pre.target static
network.target static
nss-lookup.target static
nss-user-lookup.target static
paths.target static
poweroff.target disabled
printer.target static
reboot.target disabled
remote-fs-pre.target static
remote-fs.target enabled
rescue.target disabled
rpcbind.target static
runlevel0.target disabled
runlevel1.target disabled
runlevel2.target enabled
runlevel3.target enabled
runlevel4.target enabled
runlevel5.target static
runlevel6.target disabled
shutdown.target static
sigpwr.target static
sleep.target static
slices.target static
smartcard.target static
sockets.target static
sound.target static
suspend.target static
swap.target static
sysinit.target static
system-update.target static
time-sync.target static
timers.target static
umount.target static
57 unit files listed.
lines 15-60/60 (END)
查看指定target下有哪些units:
[root@lgs ~]# systemctl list-dependencies multi-user.target
multi-user.target
● ├─auditd.service
● ├─brandbot.path
● ├─chronyd.service
● ├─crond.service
● ├─dbus.service
● ├─irqbalance.service
● ├─kdump.service
● ├─mysqld.service
● ├─network.service
● ├─NetworkManager.service
● ├─plymouth-quit-wait.service
● ├─plymouth-quit.service
● ├─postfix.service
● ├─rc-local.service
● ├─rsyslog.service
● ├─sshd.service
● ├─sysstat.service
● ├─systemd-ask-password-wall.path
● ├─systemd-logind.service
● ├─systemd-readahead-collect.service
● ├─systemd-readahead-replay.service
● ├─systemd-update-utmp-runlevel.service
● ├─systemd-user-sessions.service
● ├─tuned.service
● ├─vmtoolsd.service
● ├─basic.target
● │ ├─iptables.service
● │ ├─microcode.service
● │ ├─rhel-autorelabel-mark.service
● │ ├─rhel-autorelabel.service
● │ ├─rhel-configure.service
● │ ├─rhel-dmesg.service
● │ ├─rhel-loadmodules.service
● │ ├─[email protected]
● │ ├─paths.target
● │ ├─slices.target
● │ │ ├─-.slice
● │ │ └─system.slice
● │ ├─sockets.target
● │ │ ├─dbus.socket
● │ │ ├─dm-event.socket
● │ │ ├─systemd-initctl.socket
● │ │ ├─systemd-journald.socket
● │ │ ├─systemd-shutdownd.socket
● │ │ ├─systemd-udevd-control.socket
● │ │ └─systemd-udevd-kernel.socket
● │ ├─sysinit.target
● │ │ ├─dev-hugepages.mount
● │ │ ├─dev-mqueue.mount
● │ │ ├─kmod-static-nodes.service
● │ │ ├─lvm2-lvmetad.socket
● │ │ ├─lvm2-lvmpolld.socket
● │ │ ├─lvm2-monitor.service
● │ │ ├─plymouth-read-write.service
● │ │ ├─plymouth-start.service
● │ │ ├─proc-sys-fs-binfmt_misc.automount
● │ │ ├─sys-fs-fuse-connections.mount
● │ │ ├─sys-kernel-config.mount
● │ │ ├─sys-kernel-debug.mount
● │ │ ├─systemd-ask-password-console.path
● │ │ ├─systemd-binfmt.service
● │ │ ├─systemd-firstboot.service
● │ │ ├─systemd-hwdb-update.service
● │ │ ├─systemd-journal-catalog-update.service
● │ │ ├─systemd-journal-flush.service
● │ │ ├─systemd-journald.service
● │ │ ├─systemd-machine-id-commit.service
● │ │ ├─systemd-modules-load.service
● │ │ ├─systemd-random-seed.service
● │ │ ├─systemd-sysctl.service
● │ │ ├─systemd-tmpfiles-setup-dev.service
● │ │ ├─systemd-tmpfiles-setup.service
● │ │ ├─systemd-udev-trigger.service
● │ │ ├─systemd-udevd.service
● │ │ ├─systemd-update-done.service
● │ │ ├─systemd-update-utmp.service
● │ │ ├─systemd-vconsole-setup.service
● │ │ ├─cryptsetup.target
● │ │ ├─local-fs.target
● │ │ │ ├─-.mount
● │ │ │ ├─boot.mount
● │ │ │ ├─rhel-import-state.service
● │ │ │ ├─rhel-readonly.service
● │ │ │ └─systemd-remount-fs.service
● │ │ └─swap.target
● │ │ └─dev-disk-by\x2duuid-deb5a799\x2d817e\x2d41a2\x2d8ab5\x2d25893d3247b2.swap
● │ └─timers.target
● │ └─systemd-tmpfiles-clean.timer
● ├─getty.target
● │ └─[email protected]
● └─remote-fs.target
lines 47-92/92 (END)
target下可能含有其他target和service。
查看系统默认的target:
[root@lgs ~]# systemctl get-default
multi-user.target
设置系统默认的target:设置默认target,会创建一个软链接。
[root@lgs ~]# systemctl set-default multi-user.target
Removed symlink /etc/systemd/system/default.target.
Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/multi-user.target.
[root@lgs ~]# ls -l /etc/systemd/system/default.target
lrwxrwxrwx 1 root root 41 5月 13 13:41 /etc/systemd/system/default.target -> /usr/lib/systemd/system/multi-user.target
查看一个service是属于哪个target的:[Install]部分的WantedBy
[root@lgs ~]# cat /usr/lib/systemd/system/sshd.service
[Unit]
Description=OpenSSH server daemon
Documentation=man:sshd(8) man:sshd_config(5)
After=network.target sshd-keygen.service
Wants=sshd-keygen.service
[Service]
Type=notify
EnvironmentFile=/etc/sysconfig/sshd
ExecStart=/usr/sbin/sshd -D $OPTIONS
ExecReload=/bin/kill -HUP $MAINPID
KillMode=process
Restart=on-failure
RestartSec=42s
[Install]
WantedBy=multi-user.target
multi-user.target下的service才能设置开机启动。