32-bit and 64-bit CPU support for ESX 3.0.2

[Syik]

dear guru,

I read about 64-bit Guess OS for 64-bit CPU is supported on ESX server 3.0.2,

Questions:

1. Can I install 32-bit OS on 64-bit hardware? The KB 1912 only related to VMWorkstation 5.x version, not sure if this can apply to ESX 3.0.2

2. Can the 32-bit and 64-bit guess OS co-exist on the same 64-bit hardware.

3. Do we need specific 64-bit CPU for ESX?

Any ideas would be appreciated.

Thanks,

Shyik

[psharpley]

1. Yes

2. Yes, of course

3. Yes - for Intel they must be VT enabled. See http://www.vmware.com/support/pubs/vi_pubs.html

[lhedrick]

I am running ESX 3.0.2 and I have both 64-bit and 32-bit guests running on the same host without any issues. You do need to ensure that the server hardware supports VT and that it is enabled and if you want to run Linux you need to enable Processor Execute Disable probably as well. In the guest installation guide these requirements are listed. ( )

You do want to make sure all the hosts in your cluster are VMotion compatable if you are going to use that, otherwise you might end up with 64-bit or other guests that can not migrate.

ESX just needs an AMD or Intel x86 processor with 64-bit extensions. You need to keep all the processors the same, either Intel or AMD in the same cluster. Ideally you woudl have all the same model in a cluster that has the same processor and chipset.

[hitchcock4]

You would need a 64-bit CPU because most of the instructions are run directly on the CPU. ESX will not emulate the 64-bit instructions. It would be technically possible to run a 64-bit guest on a 32-bit CPU but the required emulation would decrease performance significantly.

For Intel, you need a processor with EM64T (see http://www.intel.com/technology/architecture-silicon/intel64/index.htm ). For AMD, you need an Opteron revision E or later. I only refer to Opteron because that will be the most common AMD processor for running ESX 3.0.

I have started testing Exchange 2007 on ESX 3.02 and Exchange 2007 is running on the 64-bit version of Windows 2003.