[TriLUG] Xen questions

[Owen Berry]

Thanks for the reply Jason. One concern of mine is the amount of memory
that I have. I seem to remember you talking about a stripped down domU
two meetings ago. Any tips? Or should I beg my manager for more memory?

Owen

On Tue, Aug 29, 2006 at 03:22:33PM -0400, Jason Tower wrote:
> xen would be perfect for your needs.  your host OS (dom0 in xen terms) 
> should run fc5 as it is very easy to get xen running.  you'll need 
> 128-256mb for the dom0 plus whatever ram you want to allocate to each guest 
> OS (domU in xen terms).
> 
> the hardest part is setting up the root filesystem for the domU, for centos 
> you'd probably use yum with the --installroot=/some/path option (i think 
> that's right).  you can either compile your own xenified centos kernel or 
> use a stock fc5 domU kernel (i do the latter with my ubuntu domUs and it 
> works fine).
> 
> the default network mode is bridge, so each domU will get its own ip 
> address just like the dom0.  there are also nat and route modes but 
> bridging is what 98% of people want.
> 
> http://www.fedoraproject.org/wiki/FedoraXenQuickstart
> 
> jason
> 
> Owen Berry wrote:
> >Some questions for those Xen and virtualization gurus out there. First,
> >some background. I run Fedora Core 4 on my workstation, but a lot of
> >what I develop ends up running on RHEL3/4 servers. Every now and then I
> >have problems because of differences in Perl modules or packaging on the
> >"production" machines. I suspect these problems will get worse over time
> >as I'm "forced" to move to more recent versions of Fedora.
> >
> >I'm wondering if I could improve my lot by using Xen to setup CentOS
> >virtual hosts on my development machine, to more closely replicate the
> >production machines. Xen appeals to me over other VM techniques
> >because of it's low overhead - I have a decent workstation but it's
> >still single CPU and 512M ram.
> >
> >1) Is this something that Xen would be good for?
> >2) Am I right in thinking that Xen would be a good virtualization
> >   choice? I have a VMWare license, but I'm thinking it'll take too much
> >   in the way of resources.
> >3) Sometimes people need to access my web server. Will I be able to
> >   forward connections to a virtual machine, possibly using mod_proxy on
> >   Apache. Or is there a more seemless way to do this? Not sure how
> >   networking works in Xen, and assuming something similar to VMWare.
> >4) I'm thinking it would be beneficial to upgrade from FC4 to FC5 before
> >   trying out Xen. Sound right?
> >
> >BTW, I don't really want to convert my workstation to running CentOS so
> >please don't suggest it, unless you feel you have to. :-)
> >
> >TIA,
> >Owen