I have a similar setup, just a generation older hardware: Win2008 x64 host, Tyan S2392, 1st gen Opteron dual-core 1.8Ghz, 12GB RAM
I see virtualization problems on Windows 2008 x64 vm's only. You may want to try if the problem goes away on a Windows 2008 x86 vm.
I checked on both a x86 and a x64 Windows 2008 vm on my rig and they both show the correct amount of memory in the Task Manager (expected RAM minus 2MB)
OK, I've done some more digging here. I checked both Task Manager and the "Properties" box of the computer. Both show the correct amount of RAM. However, I also use the wonderful "BGInfo" tool (formerly by SysInternals). In case you're not familiar with it, it replaces your background wallpaper with a text readout of various system stats such as the server's name, IP, disk space, RAM, and so on.
BGInfo consistently reports 512MB of RAM less than what's actually assigned to the VM. This has got to be something to do with the VM, because I have Win2k8 64-bit loaded on another physical machine and BGInfo shows the correct RAM amount. The issue shows up on version 6 VM's, as my version 4 VM's ported over from 1.0.5 show correct RAM in BGInfo.
So on the one hand, this is not an issue for the VM as it has the right amount of RAM as show in the OS properties. On the other hand, an application (BGInfo) is querying the OS for the RAM amount and getting the wrong number. And BGInfo only has this problem on VM's, not on real physical hardware.
Has anyone else seen issues where an application queries the OS for the total amount of RAM and gets an erroneous value?
Some memory is consumed at the kernel level, so it is not reported as used by VMware application instance.
Monitor host free physical RAM.
If BGInfo is querying total physical system RAM -- and that's what it's trying to do -- it should show the same thing as Task Manager and Computer > Properties. Host RAM consumption shows what it's supposed to show, so nothing wrong there.
This could be either a bug in BGInfo or a bug in VMWare 2.0b2. I'm somewhat inclined to think it's a bug in the VM, though, as BGInfo reports correct RAM for phyiscal servers with the same OS load (Win2K8 64-bit) as the VM in question. My concern here is if BGInfo cannot obtain the proper amount of free RAM on the VM, there may be other programs that are unable to get the right figure.