Hi guys

I'm going to be moving a linux box into collocation to support the growing demands of my sites and have been trying to figure out if Xen is right for me. I'd appreciate hearing some real-world experience with the overhead involved and the optimal ways to slice up a box. Right now I feel I should either do an all-in-one setup with a hardened installation, use Xen to virtualise services I would normally run on other machines (such as DNS and SQL) and/or use Xen to rent out VPSes.

My main concern is that I don't have unlimited resources on this box, it's a dual p4-style 3.06GHz xeon with HT and 4 gigs of old ddr. So far I am going to need to accommodate the following:
- about 100,000 script-generated page views a day, with room for spikes, floods and other attacks
- dns services for about 30 domains, only three well traveled
- sql
- mail

Is Xen practical for my situation? I'm intrigued by the ability to replace and migrate virtual servers in a snap but not sure if the performance cost makes it more effective than a traditional solution. Any input is appreciated!

You could in theory use Xen or also look at VMware Server and see if that is for you. Xen will likely give you less overhead, but possibly worse performance of guests depending on the type of work as well as if you are able to use the paravirtualization drivers.

VMware server is free now. You may also want to look at Qemu, but VMware will likely solve your problem for you. Figure on losing about <9% of your overall horsepower for the flexibility.