Try to start the server:
# service mysql start
Job for mysql.service failed. See "systemctl status mysql.service" and "journalctl -xn" for details.
Output for "systemctl status mysql.service":
mysql.service - MySQL server Loaded: loaded (/usr/lib/systemd/system/mysql.service; enabled) Active: failed (Result: exit-code) since Seg 2015-02-16 20:11:32 BRST; 1min 1s ago Process: 25103 ExecStart=/usr/lib/mysql/rcmysql start (code=exited, status=1/FAILURE)
And /var/run/mysql don't have any log.
I'm using MariaDB server.