ubuntu 18. 04 apt 直接安装的mysql ``` # MySQL systemd service file [Unit] Description=MySQL Community Server After=network.target [Install] WantedBy=multi-user.target [Service] Type=forking User=mysql Group=mysql PIDFile=/run/mysqld/mysqld.pid PermissionsStartOnly=true ExecStartPre=/usr/share/mysql/mysql-systemd-start pre ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/run/mysqld/mysqld.pid TimeoutSec=infinity Restart=on-failure RuntimeDirectory=mysqld RuntimeDirectoryMode=755 LimitNOFILE=5000 ```