Recent Posts

Checking the vNUMA Topology

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I’ve been asked a few times recently how to determine what virtual topology vNUMA recommended and created for us and besides looking at the obvious guest OS for the final result, you can also check the vmware.log file for more detailed information. Additional background here. Examples: 1) “Wide and “Flat” virtual machine – default configuration Read more...

What is PreferHT and When To Use It

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I’ve been involved recently in a couple situations in which the ‘preferHT’ advanced setting has been implemented, but for the wrong reasons. I want to re-clarify how and when it should be used. As with many advanced settings, it can be helpful or hurtful. The Myth “PreferHT exposes Hyper-Threading to the guest operating system” – Read more...

Microsoft Operating System Time Sources and Virtual Hardware 10

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More recent versions of Microsoft operating systems contain the ability to detect if they are running virtualized or not.  This is accomplished through the checking of a CPUID hypervisor-present bit presented by the VMware virtual hardware.  Since virtual hardware 7, VMware has implemented this interface, which is required by the Microsoft SVVP program. FACT: Did Read more...

Understanding vSphere Active Memory

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We’ve all seen “Active” memory reported within various vSphere interfaces, but how many us really know what it describes.  I think you might be surprised. Let’s look at its definition to get us started: Active Memory – “Amount of memory that is actively used, as estimated by VMkernel based on recently touched memory pages.” There are some Read more...

Does corespersocket Affect Performance?

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There is a lot of outdated information regarding the use of a vSphere feature that changes the presentation of logical processors for a virtual machine, into a specific socket and core configuration. This advanced setting is commonly known as corespersocket. It was originally intended to address licensing issues where some operating systems had limitations on Read more...