After installing MySQL 5.7, I do not want to start MySQL via systemctl.
It‘s unconvenient and complicated for maintainer. Actually, I like the way
that software should be installed by source package.
Solution to remove service:
systemctl disable mysql.service cd /lib/systemd/system or cd /etc/systemd/system rm mysql.service systemctl daemon-reload
Ubuntu Remove Mysql.service in Systemctl
原文：http://www.cnblogs.com/zhuangzebo/p/6534485.html