Just a heads up... If you upgrade to PHP7 you are likely to run in to problems with MySQL. I got most of my problems to go away with these tricks. apt-get install php5-mysql Add extension=mysqli.so to php.ini Tags: Could not connect to MySQL, mysqli is missing, phpmyadmin doesn't work, Application Instantiation Error!, The mysqli|mysql extension is missing.
It was all ready installed. Reason for the problems is that so much of PHP code is for v.5. Most are in the form php5-xxx and PHP7 dropped pretty much ALL support for backward compatibility.