I've hit the problem where the php mysql_connect fails with the mysql_connect function. The cause seems to be related to the fact that "localhost" is treated specially. I'm on CentOS 7.2 and using mariadb-server-5.5.47-1.el7_2.x86_64. I've some searching and found articles like this: http://alvinalexander.com/mysql/mysql_connect-cant-connect-local-mysql-server-socket I tried using mysql_connect via 127.0.0.1 instead of localhost in the test from the above link and I was able to connect. I just tried installing following the directions for CentOS 7.2: https://www.howtoforge.com/tutorial...l-php-pureftpd-postfix-dovecot-and-ispconfig/ After I complete the steps, I note that I'm not able to login and my guess is that the problem is because of the localhost issue. When installing ISPConfig, I did use 127.0.0.1 as the hostname for the database. I also tried resetting the admin password, but that didn't help either: UPDATE sys_user SET passwort = md5('admin') WHERE username = 'admin'; Is there any way to make localhost work? Or else, why do you think I'm not able to login.