centos7 編寫測試服務
bak.sh腳本內容:
cp -a /etc/sysconfig /app/sysconfig-bak >> /dev/null
bak腳本要加執行權限
服務Unit文件示例
[Unit]
Description=backup /etc
Requires=atd.service
[Service]
Type=simple
ExecStart=/bin/bash -c "echo /lib/systemd/system/bak.sh|at now"
[Install]
WantedBy=multi-user.target
運行級別
ls /usr/lib/systemd/system/*.target
`運行級別:
0 ==> runlevel0.target, poweroff.target
1 ==> runlevel1.target, rescue.target
2 ==> runlevel2.target, multi-user.target
3 ==> runlevel3.target, multi-user.target
4 ==> runlevel4.target, multi-user.target
5 ==> runlevel5.target, graphical.target
6 ==> runlevel6.target, reboot.target
`
設置默認運行級別
systemctl set-default multi-user.target
等同於創建軟鏈接:
ln -s /usr/lib/systemd/system/multi-user.target /etc/systemd/system/default.target
刪除軟鏈接使用原來默認運行級別
rm -f /etc/systemd/system/default.target