I'm installing a new server after this weekend, and it musth have both windows server 2008 r2 and linux (probably ubuntu) running, but I'm wondering which one of them I should run virtual. Windows will be used mostly for rdp and for serving asp.net webpages, linux will host some django-applications and a postgreSQL server etc.
windows crashing thats funny have seen that happen in years! its real toss up on this one though vmware vs hyper-v r2. Using vmware to host a r2 guest will be slower then r2 hosting an r2 server. But using windows to host ubuntu will be slower then vmware! I doubt either one is going to drive the server hard enough so in this case it makes no difference!
but I'd go with vmware esxi4 since there is a lot more info/documentation then hyper-v r2. Do note that hyper-v r2 is free and does include live migration, which esxi does not. Does not sound like this would be a problem in your case.
Given the history of issues I had with both Windows and (to a lesser extent) Ubuntu, I would recommend that (if you have the CPU power), you run a barebone Linux setup with something like VMware server, on top of which you would thenrun both Ubuntu and Windows in Parallel. Perhaps one drawback of such solution is that Windows will eat a lot of resources for your VM, and may so require beefed up memory and CPU. However, if it cashes, it will not take youe entire system down.
If the bare-bone server with two VMs is not an option, I would then recommend Ubuntu as the base OS and Windows as guest OS. Since Windows is more likely to crash than Ubuntu, you will have lesser chances to have to restart BOTH OSes if one of them fails.
Use Ubuntu JeOS in virtual, and windows on physical. [If memory is not an issue.]
If memory is an issue, use vice-versa.