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pdccnet
Contributor
Contributor
‎02-26-2015 10:09 AM

Win7 VM shows Memory Module error

Running Fusion 7.1.1 (2498930) on a PowerMac with OS X 10.9.5. 64GB on the host machine. I've created a Win7 VM with 4GB of RAM (4096MB showing in the preferences panel).

With the VM running, I go to Start>Control Panel>Administrative Tools>Computer Management (I know there are other ways to get there... I'm just giving general path so you can follow me).

Within Computer Management, I select Device Manager and see the "Memory devices" expanded and showing TWO devices named "Memory Module". One is fine but one has the "yellow bang" on it. Looking at the properties on the "errored" Memory Module shows a Device status that states: "This device cannot start. (Code 10)"

I searched the VMware Communities & KB. Only related article I found was here: Re: VMware 10 shows memory module error

The "answer" cited in that article makes no sense. The argument is that Win 7 supports up to 4GB of RAM. Older OS's don't. The user in that thread is setting his RAM to 3GB. No explanation of how to get rid of the "error" except for someone noting that if you set the RAM to 2GB, the errored module goes away (i.e., only one Memory Module shows up if you specify 2GB RAM).

I'm stumped as to why I'm seeing a "disabled" memory module and what effect, if any, this is having on my VM.

Hope someone can address this.

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dariusd
VMware Employee
VMware Employee
‎02-26-2015 10:42 AM

In Device Manager, choose View > Resources by connection, and expand the Memory section.  That will show the address space layout for the virtual machine.

Many 32-bit guest OSes only support 4 GBytes of address space, 0x00000000 to 0xFFFFFFFF inclusive, of which a moderately-large region is reserved for PCI/PCIe devices and various system devices (that region is called the "PCI hole").  So you will only be able to use the RAM which can be squeezed in below the PCI hole, usually from around the bottom of RAM up to 0xBFFFFFFF.  Virtual machines with more than 3072 MBytes of RAM will end up with some RAM located above the 4GByte space (i.e. at or above 0x100000000), which is unusable unless the guest OS supports accesses above 4 GBytes.

Hope this helps!

--

Darius

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