• This is the first diagram of more ESX blueprints to come. Previously I was focused more onto the vSphere architectures as a whole, but there will be more granular diagrams on ESX itself as a hypervisor very soon.
• The colors play a major role in this diagram. I thought I should stick with the original colors used in the vCenter Server Recourse monitoring box (on the top right of the diagram) instead of reinventing the wheel. As an example, if you want to scan through the swapping memory reclamation technique, all what you need is to focus your sight on the red colors. Whether it’s in the VMs, hypervisor, esxtop or vCenter, the red color will always relate to the swapping activity, and so forth.
• In the MMU virtualization I did not put much detail (as I was hoping to) because of the diagram limited space, but I’m planning to make more detailed diagrams about this topic in the future, along with other technologies like NUMA and EPT/RVI for example.
• In the memory reclamation techniques, you might have noticed that the “idle memory tax” is not there. I intend to illustrate that in a deferent topic related to shares and resource management.
• The Memory compression and swapping to SSD are future features coming soon in the vSphere generation. This information was mentioned in the VMworld 2009 session TA2627 so it’s public.
• The most interesting part for me while creating this diagram was the ESXTOP. I have a wild idea of creating a crazy huge diagram (poster-like) and add the deferent screens and options for ESXTOP along with real-world numbers and descriptions to show the beauty of this incredible tool. I might also use Duncan’s esxtop section as a reference for the thresholds, I urge you to go there and share your experience!
• For some reason, the PDF converter kept converting the ESXTOP text box into an image and then down-sample it, which ended up not looking as sharp and clean as in the original Visio diagram. I’m trying to figure out why the Acrobat is giving me this grief, so I will probably update the PDF later on (check the version numbers).
• I’ve received a number of emails asking for some descriptions accompanying my diagrams (like the admission control calculations in the HA diagram), and I believe you are right about that, especially for the newbies entering the fascinating world of VMware. I’ll revisit these diagrams in the future with detailed descriptions and write-ups, so stay tuned.

I hope you’ll like this diagram and see the real beauty of the ESX memory management (well a glimpse of it at least). If you have any corrections or suggestions please drop a comment or email and let me know your thoughts.

Recourses:
- Book: Operating System Concepts (Part Three – Memory Management)
- Book: Modern Operating Systems 3rd Edition (Chapter 3 – Memory Management)
- Documentation: vSphere Resource Management Guide
- WP: Understanding Memory Resource Management in VMwareо ESX™ Server
- WP: Memory Resource Management in VMware ESX Server – by Carl A. Waldspurger
- VMworld2009 Session: TA2963 “esxtop for advanced users”
- VMworld2009 Session: TA2627 “Understanding “Host” and “Guest” Memory Usage and Related Memory Management Concepts”
- Blog: Arnim van Lieshout (Part-1 , Part-2, Part-3)