4 Replies Latest reply on May 1, 2008 11:48 AM by prisoner881

    VMWare 2.0Beta2 - x64 guest showing incorrect amount of RAM

    prisoner881 Enthusiast
      Host: Windows 2008 x64, Tyan S3950 AM2 motherboard, Opteron dual-core 2.2GHz, 8GB RAM   Guest #1: Windows 2008 x64, uniprocessor, allocated 4096MB of RAM, 50GB virtual disk Guest #2: Windows 2003 R2 x64, uniprocessor, allocated 512MB of RAM, 16GB virtual disk     Guest #1 is only showing 3580MB of RAM instead of expected 4096MB. Increased Guest #1 RAM to 5120MB, but now only shows 4607MB. Guest #1 seems to be missing about 512MB in each case. VM is version 6.    Guest #2 is VM version 4 (ported over from VMWare Server 1.0.5) and shows 512MB of RAM correctly.    Anybody else have their VM's showing less RAM than what was allocated? 
        • 1. Re: VMWare 2.0Beta2 - x64 guest showing incorrect amount of RAM
          kreeuwij Novice

          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)

          • 2. Re: VMWare 2.0Beta2 - x64 guest showing incorrect amount of RAM
            prisoner881 Enthusiast

            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?

            • 3. Re: VMWare 2.0Beta2 - x64 guest showing incorrect amount of RAM
              Peter_vm Guru

              Some memory is consumed at the kernel level, so it is not reported as used by VMware application instance.

              Monitor host free physical RAM.

              • 4. Re: VMWare 2.0Beta2 - x64 guest showing incorrect amount of RAM
                prisoner881 Enthusiast

                 

                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.