One of the things VMware’s products allow administrators to do is space out hardware upgrades, but that will soon change with the release of VMware vSphere. VMware vSphere’s hypervisor uses a 64-bit kernel. What this means is that vSphere ESX 4 is a 64-bit operating system that requires 64-bit hardware.
Granted, you have probably already upgraded to quad-core technologies which means you are probably safe, but those using dual-core technologies may not be. Case in point: HP DLxx0 G4 platforms. These are somewhere between 32- and 64-bit with EMT64 support, but unfortunately this is not enough to run VMware vSphere 4. You will need actual 64-bit hardware. Hopefully you can attain this with just a CPU change.
AMD processors have been 64-bit for some time so those with an investment in AMD processors and systems may not have to worry about such an upgrade.
For me, this requirement meant purchasing brand new hardware months ago to run the vSphere 4 beta.
The rest of you will have to make a choice, move to vSphere 4 and possibly upgrade your hardware all at once, or take a staged approach and do your hardware upgrade while still using VMware Infrastructure 3 until all your systems are on the hardware compatibility list for vSphere 4. At that time you can consider upgrading to vSphere 4 — or not.
Editor’s Note: See Eric Siebert’s article VMware vSphere: Got 64-bit hardware? for additional information on the 64-bit hardware requirement.