We would like to employ Active Directory to handle duties including DNS, LDAP, domain-controller stuff, etc. The obvious way to do this would be to install Windows and run AD from there. However, we are almost exclusively a Linux shop, and are contemplating running Windows on a VM hosted on Linux. Does this sound like a plausible plan or a recipe for pain? If it is reasonable, are there any significant differences in performance between VMWare and VirtualBox given the sort of tasks we are going to ask the Windows installation to do?
Additionally, there may come a time in the near future in which we might want to host an Exchange server. If this does come to pass, is it preposterous to try to run Exchange on a Windows VM hosted on Linux?