linux mysqlをインストールして電源を切る時よくハングアップします

linux mintはmysqlをインストールした後、シャットダウンまたは再起動できません.rebootの場合はいつもmysqlが閉じたプロセスに止まります.

a stop job is running for mysql community 

ソリューションリファレンス:https://askubuntu.com/questions/615129/systemd-mysql-wont-stop

had the same problem (upgrade to 15.04, using official files and config).

I had to make the following changes to be able to stop the mysql daemon manually with sytemctl and automatically on system reboot/shutdown:

    Make /etc/mysql/debian.cnf readable for the mysql user with

    sudo chgrp mysql /etc/mysql/debian.cnf; sudo chmod 640 /etc/mysql/debian.cnf

    Provide a slightly modified mysql.service file:

    sudo cp /lib/systemd/system/mysql.service /etc/systemd/system/
    sudo chmod 755 /etc/systemd/system/mysql.service

    Provide an explicit stop command by opening the copied file in an editor:

    sudo nano /etc/systemd/system/mysql.service

    and adding the following line under the [Service] section:

    ExecStop=/usr/bin/mysqladmin --defaults-file=/etc/mysql/debian.cnf shutdown

    In Nano, use Ctrl+O to save (Linux way!), Ctrl+X to exit.

    Make the new service file known to system:

    sudo systemctl daemon-reload