Many web applications, including Magento need PHP5.2 to function. If your server doesn’t have PHP 5.2, there’s a simple way to upgrade.
Using SSH, logon to your server.
Use these commands:
wget -q -O – http://www.atomicorp.com/installers/atomic.sh |sh
yum update php
/usr/local/psa/admin/sbin/websrvmng -a
/etc/init.d/httpd reload
That’s it!