Whenever /var/run/mysqld doesn't exist, these lines show up in /var/log/mysql/error.log:
2015-03-24 17:43:15 1178 [Note] Server hostname (bind-address): '127.0.0.1'; port: 3306
2015-03-24 17:43:15 1178 [Note] - '127.0.0.1' resolves to '127.0.0.1';
2015-03-24 17:43:15 1178 [Note] Server socket created on IP: '127.0.0.1'.
2015-03-24 17:43:15 1178 [ERROR] Can't start server : Bind on unix socket: No such file or directory
2015-03-24 17:43:15 1178 [ERROR] Do you already have another mysqld server running on socket: /var/run/mysqld/mysqld.sock ?
2015-03-24 17:43:15 1178 [ERROR] Aborting
Here is the relevant logs.
Whenever /var/run/mysqld doesn't exist, these lines show up in /var/log/ mysql/error. log:
2015-03-24 17:43:15 1178 [Note] Server hostname (bind-address): '127.0.0.1'; port: 3306 mysqld/ mysqld. sock ?
2015-03-24 17:43:15 1178 [Note] - '127.0.0.1' resolves to '127.0.0.1';
2015-03-24 17:43:15 1178 [Note] Server socket created on IP: '127.0.0.1'.
2015-03-24 17:43:15 1178 [ERROR] Can't start server : Bind on unix socket: No such file or directory
2015-03-24 17:43:15 1178 [ERROR] Do you already have another mysqld server running on socket: /var/run/
2015-03-24 17:43:15 1178 [ERROR] Aborting