Hi people.

We are working on a new ERP for the company. This will run in MySQL 5.1.x, the GUI will be Web, the language PHP.

This is a big project, is a good option to have the 3 applications in the same server or is better to have Mysql on 1 server and httpd+php on other server?

Speaking that I want to virtualize this app with Xen on Centos 5.5 as Host and the guest's will run Ubuntu.

Any recommendation will be appreciated, thanks!!!

P.S. I have been never run MySQL for project like this size.

You should run MySQL on a single server and Apache + PHP on a second server. This is a good security practice so that if one server is compromised you don't lose everything. If you wanted to add an extra layer of security you could also setup a proxy server between the Apache server and your end users, this way they never see the IP addresses of your internal servers (Apache + MySQL). The MySQL setup is really simple there are plenty of guides on google to get you going. I will note that you shouldn't use the "root" user for MySQL connections from your web server. Create a secondary user for the application and only grant rights for that user to access certain parts of the database.

Let me know if you have any other questions

Thanks for your tip.

I already have a proxy running inside.

Yes, I normally never run app with the root user.

Running 2 mysql server like a replica can increase my performance?

Thanks again!!!

It wouldn't really increase the performance but it will provide you with failover in case one server dies.