I'm planning on building an Ubuntu server that primarily needs to be a file server, but due to budgetary constraints will likely get used for running virtual images for a couple of different development / server projects (probably rarely concurrently; will be mostly testing).
I have looked into various virtualisation solutions (Xen, KVM, VirtualBox) and am currently thinking I will go with KVM, although I'm new to this in a server context (I've used Virtual PC on Windows extensively).
My question is: Should I go "the whole hog" and have everything virtualised or should I just virtualise the additional OSs and keep the file server at the host level?
I would instinctively have gone for virtualising everything, but if I'm using a virtual server for the file server I presume this would result in some massive single file on the host that contained all my file servers files. I was just concerned this might cause potential issues (I know fairly large files are fine but I wasn't sure how big would be okay and if say 500Gb might start to become a problem!)
The other thing is that perhaps I'm missing a trick here, due to my relative new-ness with KVM and server virtualisation. (at the risk of sounding very uninformed...) Is it necessary that the files the file server reside in that image or perhaps can they reside at the host OS level and still have the file server responsible for serving them to my network?
More specifics in case they help:
Intended Host OS: Ubuntu 9.10 Server
Guest OSs: most are likely to be Ubuntu 9.10 Server but ideally I'm hoping to use Windows 7 for testing on a particular project.
Guest OS uses anticipated to include: (potentially) file server; a mediawiki install (plus a test version); web server (Apache) for some simple internal use webpages that can't be on the same machine as the mediawiki machine; Win7 test machine;
For all access I'm planning on connecting remotely with SSH (although I'll be in the same location as the server the majority of the time
Any (constructive) advice gratefully received!