I have searched high and low using Google and Bing. I have checked the guidance, including designing SharePoint 2010 for virtualisation on TechNet, and I have not found any mention of Dynamic Memory. Let’s assume that SharePoint does support Dynamic Memory – unless you do have an abundance of support calls with CSS or Premier and can get an answer (please do share!).
Two things stand out:
The key to performance of SharePoint appears, to me, to be SQL Server. We already know the story for SQL and Dynamic Memory.
The sizing guidance for SP 2010 is quite realistic. There’s a lot of “it depends” and talk of user acceptance testing. In Ireland we call it “suck it and see”. In other words, you won’t know what’s the right sizing for your environment until you try it. Memory guidance uses the word “estimated” quite a bit. Based on my previous experience with SharePoint (which is limited, I admit), MS sizing tends to be for huge user bases and not those that most of us deal with. I remember a “small” SP 2003 farm from an MS Press book being 10,000 users. I was sizing for 800 at the time, and MS Ireland considered us to be an enterprise customer!
You will need flexibility. That leaves me thinking that SharePoint is the perfect candidate for Dynamic Memory. You will have to estimate that maximum memory, and the hypervisor will take care of assigning only what is required. Later on (after monitoring) you can decide to reduce or increase the maximum memory setting.
I will update this post if I hear anything definitive.