I'm developing an e-commerce site in a LAMP environment. Is it advisable to separate data on to different servers (i.e. to have one server as the web server and another server to house transaction and other customer data)? In other words, from a security perspective is there any reason why I should not house all the data both for the e-commerce webshop and all backend customer and transaction data on a single machine and even in a single database)? [with daily backups of course].