PHP upgrading to 5.3.3 - what should I be aware of?

Question

I have a VPS that's hosting half a dozen PHP-based sites. All is OK on php5.2.10 but I want to upgrade to 5.3.3.

I have tested the functionality of the sites on my local dev machine running 5.3.1 and all is well.

Having never done a PHP upgrade, and not wanting to disrupt the service of the live sites, are there any precautions you can give me that I should be considereing before I do this?

Thanks.

Answer 1

Testing on another computer is a good way to start, but to have the best result try to test with 5.3.3 and on a computer that look like as much as possible the server configuration. A virtual machine is a good way to duplicate server setup and test an upgrade.
You also want to read http://www.php.net/manual/en/migration53.php to understand change between 5.2 and 5.3 so that you will see if you can have any potential issue.