On 12.02.2009, at 20:40, Eliot Miranda wrote:
- a 32-bit VM compiled to run 32-bit images
- a 32-bit VM compiled to run 64-bit images
- a 64-bit VM compiled to run 32-bit images
- a 64-bit VM compiled to run 64-bit images
Speaking through a self-imposed gag let me suggest the FAQ distinguish clearly between a 64-bit VM (meaning a VM that runs 64- bit images that necessarly is compiled as a 64-bit executable) and a 32-bit VM compiled to run as a 64-bit executable. The latter doesn't count as a 64-bit VM for me. 64-bit clean perhaps.
It may not count for you but that's how we have been calling it. Since nobody expects 64 bit images to work "64-bit" VM refers to the host architecture. I'm not quite sure how we could phase out that nomenclature.
Let me further suggest that 2) is pointless, in that it can't scale beyond the 32-bit address space but uses about 1.5 times the space of a 32-bit image as it tries to do so. i.e. it'll fail a lot earlier than a 32-bit image. Further, if a 64-bit image is larger than will fit in a 32-bit address space one *cant* run it on 2 because it won't fit.
The point of this was not to be used in production but to *create* VM for running a 64 bit image without having to use a 64 bit host.
So I would suggest the FAQ explain tat there are really three different VMs, two 32-bit ones and one 64-bit one. One of the 32- bit VMs is compiled to run as a 64-bit executable on 64-bit systems but only runs a 32-bit image. That at least accords with the planet I grew up on :)
Only if you want to use 64 bit images. Which nobody wants. Yet.
- Bert -