[CentOS-virt] Mixed dom0/domU usage?

Hi, I'm wondering about the impact of using both dom0 and domU's on a server at the same time. I'm worried about the performance impact of running a Mysql server in a domU and now I'm thinking about moving the Mysql part of a LAMP setup into dom0 and running a few Apache guests as domUs. Since the Apaches will serve mostly from an NFS share they won't have much impact on the disk i/o so the database should be able to utilize the local storage without much interference from the guests. The plan is to limit dom0 to let's say 4gb of ram and then use the rest of it for the VMs.

Has anyone experinece with this kind of "mixed" setup (physical/virtual). Are there any known problems with this approach?

Regards, Dennis