[Setup] Zope virtualization

[Shaun Hills]

Hello,

We're evaluating the best way to upgrade our moderate traffic (200-300k
uniques/mth) Plone sites. Currently we run everything on a single 4GB server
using ZEO, though all but our most heavily-trafficked sites only run one ZEO
client. Each Plone site  - we have something like 5 - is in a separate Zope. We
also run MySQL and a few other minor bits and pieces (e.g. some PHP scripts) on
the server.

We're looking to move to a more "classical" ZEO client/server arrangement, with
a big-ish ZODB/MySQL server backend, and ZEO clients and proxy caches on smaller
front-end boxes. Somthing like this:

|ZODB/MySQL| <--> |ZEO/PHP| <--> |Proxy/cache|

However our budget doesn't stretch too far and someone has suggested
virtualization instead. So we would have the same architecture as above, but on
a single beefed up machine running multiple VMs.

It sounds like a good idea, but my main concerns are:

1) RAM - we need lots of it, and ideally it shouldn't be shared.
2) It's not a common setup i.e. may be hard to get support

Is this a recommended strategy? Has anyone run Zope in a virtualisation
environment before? Anything we should watch out for?

Or, is the idea a non-starter?

thanks

 - Shaun