I understand from the VMware Server 2 documentation that VMware Server 2 is capable of running a 64-bit guest OS underneath a 32-bit host OS, as long as the hardware running the box is 64-bit capable.
Here's my situation. We currently have an underutilized XEON X3220 Quad Core 64bit Server, running Server 2003, 32-bit and 2gb of RAM (the motherboard is capable of 8gb ram). The server is currently used mainly for file and print services. It is also running Active Directory, Novell eDirectory and Groupwise 6.5. We are planning a micration to Microsoft Exchange, so the Novell eDirectory and Groupwise services will eventually be purged from this box, leaving only Active Directory, File and Print services.
Being that this server is underutilized we are hoping to save hardware costs and virtualize our new Exchange investment. My question is this. Will VMware allow access to the "invisible" extra memory that Windows 32-bit won't see. Meaning, if we increase the full amount of system ram to 8gb (yes, I know the 32-bit host OS will only see a maximum of 4gb), will I be able to assign maybe 5gb to the new Server 2008 64-bit OS running Exchange and leave 3gb for the Guest OS (or maybe even a 6, 2 split).
The second part of that would be, would it be better to just convert the main OS currently running to an image, convert the machine itself to ESXi and run both OSes as images under ESXi.
Downtime for this box is critical, so my preference is most definitly with the first option because it presents very minimal downtime. Doing the second would make downtime quite a few hours to image the machine and then convert the image to a VMware Image.