Update PHP 5.4 on Debian 6 Squeeze Rumi, June 6, 2014 Set up Dotdeb First add Dotdeb to your Apt sources: sudo vim /etc/apt/sources.list /etc/apt/sources.list deb http://packages.dotdeb.org squeeze all deb-src http://packages.dotdeb.org squeeze all deb http://packages.dotdeb.org squeeze-php54 all deb-src http://packages.dotdeb.org squeeze-php54 all Save & Exit. Now go for the next- curl http://www.dotdeb.org/dotdeb.gpg | sudo apt-key add -sudo apt-get update Now Install PHP 5.4 sudo apt-get dist-upgrade Test it- php -v I found there were a couple of warning messages – I had to remove the old Suhosin & APC configuration files, and manually re-install APC: sudo rm /etc/php5/conf.d/suhosin.ini sudo rm /etc/php5/conf.d/apc.ini sudo apt-get install php5-apc Optionally install MySQL 5.5 If you get this message: The following packages have been kept back: mysql-server It’s probably because Dotdeb includes MySQL 5.5 and Squeeze includes MySQL 5.1. You can choose to upgrade with this command: sudo apt-get install mysql-server You may find phpMyAdmin gives a warning like this: Your PHP MySQL library version 5.1.66 differs from your MySQL server version 5.5.30. This may cause unpredictable behavior. You can fix this by installing the new MySQL Native Driver extension: sudo apt-get install php5-mysqlnd Administrations Configurations (Linux) Debianphp