[CentOS-virt] Mixed dom0/domU usage?

Wed Feb 4 09:17:16 UTC 2009
Tim Verhoeven <tim.verhoeven.be at gmail.com>

On Wed, Feb 4, 2009 at 10:03 AM, Dennis J. <dennisml at conversis.de> wrote:
> 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?


On a performance level it shouldn't make that much of a difference.
But a domU will have some more overhead in I/O. So it make sence to
run your DB in the dom0.

The only thing to remember is that when something happens to your dom0
the domU's will most likely also be impacted. So that your need to
keep in the back of your head.


Tim Verhoeven - tim.verhoeven.be at gmail.com - 0479 / 88 11 83

Hoping the problem  magically goes away  by ignoring it is the
"microsoft approach to programming" and should never be allowed.
(Linus Torvalds)