Linux8.5 任务计划及系统服务
Linux任务计划cron
任务计划配置文件
[root@chyuanliuNJ ~]# 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
crontab -e 定义任务计划，不写用户，默认执行root用户
#指定任务计划 #格式 ： 分 时 日 月 周 user command #范围 ： 0-59 0-23 0-31 0-12 1-6 #可用格式 ： 1-5表示一个范围1到5 ； 1,2,3表示1或者2或者3 #可用格式 ： */2表示被2整除的数字，比如小时，那就是每隔2小时，双数时间 [root@chyuanliuNJ ~]# crontab -e 0 3 * * * /bin/bash /usr/local/sbin/123.sh >>/tmp/123.log 2>>/tmp/123.log
使用星期去确定唯一性，今年的8月16和明年的8月16星期肯定不一样。
要保证服务的启动。 systemctl start crond
查看cron服务状态。绿色则启动。 systemctl status crond
切记，任务计划和shell脚本里的一切命令都用绝对路径。每写一个任务计划都要追加日志，可以保证该任务有据可查。
备份任务计划，以用户名字命名的文件名
[root@chyuanliuNJ ~]# cat /var/spool/cron/root 0 3 * * * /bin/bash /usr/local/sbin/123.sh >>/tmp/123.log 2>>/tmp/123.log
[root@chyuanliuNJ ~]# crontab -l 0 3 * * * /bin/bash /usr/local/sbin/123.sh >>/tmp/123.log 2>>/tmp/123.log
基本操作
#列出 [root@chyuanliuNJ ~]# crontab -l 0 3 * * * /bin/bash /usr/local/sbin/123.sh >>/tmp/123.log 2>>/tmp/123.log #指定用户列出 [root@chyuanliuNJ ~]# crontab -u root -l 0 3 * * * /bin/bash /usr/local/sbin/123.sh >>/tmp/123.log 2>>/tmp/123.log #删除 [root@chyuanliuNJ ~]# crontab -r [root@chyuanliuNJ ~]# crontab -u root -l no crontab for root
Linux系统服务管理-chkconfig
管理服务，控制服务开机启动、指定级别启动等。centos7中已经不用，趋势移弃。
[root@chyuanliuNJ ~]# chkconfig --list
Note: This output shows SysV services only and does not include native
systemd services. SysV configuration data might be overridden by native
systemd configuration.
If you want to list systemd services use 'systemctl list-unit-files'.
To see services enabled on particular target use
'systemctl list-dependencies [target]'.
aegis 0:off 1:off 2:on 3:on 4:on 5:on 6:off
agentwatch 0:off 1:off 2:on 3:on 4:on 5:on 6:off
cloudmonitor 0:off 1:off 2:on 3:on 4:on 5:on 6:off
mysqld 0:off 1:off 2:on 3:on 4:on 5:on 6:off
netconsole 0:off 1:off 2:off 3:off 4:off 5:off 6:off
network 0:off 1:off 2:on 3:on 4:on 5:on 6:off
php-fpm 0:off 1:off 2:on 3:on 4:on 5:on 6:off
staragentctl 0:off 1:off 2:on 3:on 4:on 5:on 6:off
服务脚本在 /etc/init.d目录下
停止服务
[root@chyuanliuNJ ~]# chkconfig aegis off
[root@chyuanliuNJ ~]# chkconfig --list
Note: This output shows SysV services only and does not include native
systemd services. SysV configuration data might be overridden by native
systemd configuration.
If you want to list systemd services use 'systemctl list-unit-files'.
To see services enabled on particular target use
'systemctl list-dependencies [target]'.
aegis 0:off 1:off 2:off 3:off 4:off 5:off 6:off
agentwatch 0:off 1:off 2:on 3:on 4:on 5:on 6:off
cloudmonitor 0:off 1:off 2:on 3:on 4:on 5:on 6:off
mysqld 0:off 1:off 2:on 3:on 4:on 5:on 6:off
netconsole 0:off 1:off 2:off 3:off 4:off 5:off 6:off
network 0:off 1:off 2:on 3:on 4:on 5:on 6:off
php-fpm 0:off 1:off 2:on 3:on 4:on 5:on 6:off
staragentctl 0:off 1:off 2:on 3:on 4:on 5:on 6:off
#在某级别为开服务还是关闭服务
指定开某服务的某级别
[root@chyuanliuNJ ~]# chkconfig aegis --level 3 on
[root@chyuanliuNJ ~]# chkconfig --list
Note: This output shows SysV services only and does not include native
systemd services. SysV configuration data might be overridden by native
systemd configuration.
If you want to list systemd services use 'systemctl list-unit-files'.
To see services enabled on particular target use
'systemctl list-dependencies [target]'.
aegis 0:off 1:off 2:off 3:on 4:off 5:off 6:off
... ...
[root@chyuanliuNJ ~]# chkconfig aegis --level 245 on
[root@chyuanliuNJ ~]# chkconfig --list
Note: This output shows SysV services only and does not include native
systemd services. SysV configuration data might be overridden by native
systemd configuration.
If you want to list systemd services use 'systemctl list-unit-files'.
To see services enabled on particular target use
'systemctl list-dependencies [target]'.
aegis 0:off 1:off 2:on 3:on 4:on 5:on 6:off
... ...
在服务列表加入服务
Sytemd管理服务
systemctl list-units --all --type=service [root@chyuanliuNJ ~]# systemctl list-units --all --type=service UNIT LOAD ACTIVE SUB DESCRIPTION aegis.service loaded active running LSB: aegis update. agentwatch.service loaded active exited SYSV: Starts and stops g aliyun.service loaded active running auto run aliyunservice o apachectl.service loaded active running (null) atd.service loaded active running Job spooling tools ● auditd.service loaded failed failed Security Auditing Servic brandbot.service loaded inactive dead Flexible Branding Servic cloud-config.service loaded active exited Apply the settings speci cloud-final.service loaded active exited Execute cloud user/final cloud-init-local.service loaded active exited Initial cloud-init job ( ● cloud-init-upgrade.service loaded failed failed cloud-init upgrade servi cloud-init.service loaded active exited Initial cloud-init job ( cloudmonitor.service loaded active running LSB: @app.long.name@ cpupower.service loaded inactive dead Configure CPU power rela crond.service loaded active running Command Scheduler dbus.service loaded active running D-Bus System Message Bus ● display-manager.service not-found inactive dead display-manager.service dracut-shutdown.service loaded inactive dead Restore /run/initramfs ... ... 几个常用服务相关命令 systemctl enable crond.service 让服务开机启动 systemctl disable crond 不让开机启动 systemctl status crond 查看状态 systemctl stop crond 停止服务 systemctl start crond 启动服务 systemctl restart crond 重启服务 systemctl is-enabled crond 检查服务是否开机启动
unit介绍
系统所有unit,分有很多类型
service 系统服务，比如httpd target 多个unit组成的组，之前 device 硬件设备 mount 文件系统挂载点 automount 自动挂载点 path 文件或路径 scope 不是由systemd启动的外部进程 slice 进程组 snapshot systemd快照 socket 进程间通信套接字 swap swap文件 timer 定时器
[root@chyuanliuNJ ~]# ls /usr/lib/systemd/system arp-ethers.service atd.service auditd.service autovt@.service basic.target basic.target.wants blk-availability.service bluetooth.target brandbot.path brandbot.service chrony-dnssrv@.service chrony-dnssrv@.timer ... ...
target类似运行级别
[root@chyuanliuNJ system]# ls -l runlevel* lrwxrwxrwx 1 root root 15 Aug 18 11:57 runlevel0.target -> poweroff.target lrwxrwxrwx 1 root root 13 Aug 18 11:57 runlevel1.target -> rescue.target lrwxrwxrwx 1 root root 17 Aug 18 11:57 runlevel2.target -> multi-user.target lrwxrwxrwx 1 root root 17 Aug 18 11:57 runlevel3.target -> multi-user.target lrwxrwxrwx 1 root root 17 Aug 18 11:57 runlevel4.target -> multi-user.target lrwxrwxrwx 1 root root 16 Aug 18 11:57 runlevel5.target -> graphical.target lrwxrwxrwx 1 root root 13 Aug 18 11:57 runlevel6.target -> reboot.target ... ... #target就是多个Unit组成的一个组，形成的一个target
unit的相关命令
[root@chyuanliuNJ system]# systemctl list-units #列出正运行的unit ... ... sockets.target loaded active active Sockets 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 Tem 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. 102 loaded units listed. Pass --all to see loaded but inactive units, too. To show all installed unit files use 'systemctl list-unit-files'. [root@chyuanliuNJ system]# systemctl list-units --all #列出所有，包括失败的或者inactive的 #列出所有inactive的unit [root@chyuanliuNJ system]# systemctl list-units --all --state=inactive #列出状态为active的service [root@chyuanliuNJ system]# systemctl list-units --type=service #查看某个服务是否为active [root@chyuanliuNJ system]# systemctl is-active crond.service active
target介绍
系统为了方便管理用target来管理unit
#一个target就是多个Unit组合，用target来管理unit，列出所有的target [root@chyuanliuNJ system]# systemctl list-unit-files --type=target UNIT FILE STATE basic.target static bluetooth.target static cloud-config.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 ... ...
查看指定target下面有哪些unit
[root@chyuanliuNJ system]# systemctl list-dependencies multi-user.target multi-user.target ● ├─aegis.service ● ├─agentwatch.service ● ├─apachectl.service ● ├─atd.service ● ├─auditd.service ● ├─brandbot.path ● ├─cloud-config.service ● ├─cloud-final.service ● ├─cloud-init-local.service ... ... #查看指定target下面有哪些unit
查看系统默认的target
[root@chyuanliuNJ system]# systemctl get-default multi-user.target
设置默认的target，同样也会创建一个软链接
[root@chyuanliuNJ system]# 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.
一个service属于一种类型的unit，多个Unit组成了一个target，一个target里面包含了多个service
[root@chyuanliuNJ system]# 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 RestartPreventExitStatus=255 [Install] WantedBy=multi-user.target
