64bit Guest OS Memory Usage

dlbenson1979 used Ask the Experts™
I have what I think is a simple question concerning 64bit Guest VMs in VMWare.

If I create a 64bit guest OS and give it 6 GB of RAM, will it stop taking my host memory at 6GB or will it keep grabbing as much memory as it can?

In this example, I don't want to consider Resource Pools.
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It will keep grabbing RAM unless and until you restrict it using the Resource Allocation Tab of your ESX Host using VI Client.


This would bring me to another question: Does this specifically need to be done through the ESX host VI client or can you do this through VCenter?
If you are using vCenter, the same can be achieved.

The Hypervisor (in this case VMWare) creates a virtual
environment for the guest which has exactly the amount
of memory you've configured.

The guest is unable to use more memory than that from your host. The Hypervisor does require a little additional memory per guest machine for administrative purpose. But the guest doesn't "see" it.

The memory management of VMWare makes it possible to allocate more memory to VM's than you really have in your host. It can allocate unused memory of one guest  to another - within the configured memory limit.

Bite take care, if you over commit memory you could see a major performance impact if the guest's really want to use the committed memory.

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