Job for mysqld.service failed See "systemctl status mysqld.service"

This amazingly worked.

/etc/init.d/mysql stopservice mysql stopkillall -KILL mysql mysqld_safe mysqld/etc/init.d/mysql startservice mysql start

I met this problem today, and fix it with bellowed steps.

1, Check the log file /var/log/mysqld.log

tail -f /var/log/mysqld.log 2017-03-14T07:06:53.374603Z 0 [ERROR] /usr/sbin/mysqld: Can't create/write to file '/var/run/mysqld/mysqld.pid' (Errcode: 2 - No such file or directory) 2017-03-14T07:06:53.374614Z 0 [ERROR] Can't start server: can't create PID file: No such file or directory

The log says that there isn't a file or directory /var/run/mysqld/mysqld.pid

2, Create the directory /var/run/mysqld

mkdir -p /var/run/mysqld/

3, Start the mysqld again service mysqld start, but still fail, check the log again /var/log/mysqld.log

2017-03-14T07:14:22.967667Z 0 [ERROR] /usr/sbin/mysqld: Can't create/write to file '/var/run/mysqld/mysqld.pid' (Errcode: 13 - Permission denied)2017-03-14T07:14:22.967678Z 0 [ERROR] Can't start server: can't create PID file: Permission denied

It saids permission denied.

4, Grant the permission to mysqlchown mysql.mysql /var/run/mysqld/

5, Restart the mysqld

# service mysqld restartRestarting mysqld (via systemctl):                         [  OK  ]

These are the steps I took to correct this:

Back up your my.cnf file in /etc/mysql and remove or rename it

sudo mv /etc/mysql/my.cnf /etc/mysql/my.cnf.bak

Remove the folder /etc/mysql/mysql.conf.d/ using

sudo rm -r /etc/mysql/mysql.conf.d/

Verify you don't have a my.cnf file stashed somewhere else (I did in my home dir!) or in /etc/alternatives/my.cnf use

sudo find / -name my.cnf

Now reinstall every thing

sudo apt purge mysql-server mysql-server-5.7 mysql-server-core-5.7sudo apt install mysql-server

In case your syslog shows an error like "mysqld: Can't read dir of '/etc/mysql/conf.d/'" create a symbolic link:

sudo ln -s /etc/mysql/mysql.conf.d /etc/mysql/conf.d

Then the service should be able to start with sudo service mysql start.

I hope it work