Hard to believe it has been eight months since my last post.  I've been deep into Windows Sercurity and Reliabiltiy and was fortunate enough to have a chance to contribute to one of the two features I'm briefly blogging about today - RemoteFX.

So what are RemoteFX and Dynamic Memory? 

RemoteFX is the next step in plumbing direct access to hardware in Virtual Machines (VM).  Today Hyper-V gives direct access to disk (passthrough disks) and networking (VMQ and WinSockDirect).  What is new with RemoteFX is the tie to hardware is even deeper for graphics.  For example RemoteFX allows you to create and run a DirectX Shader in your VM.  Having this level of graphics control and power in a VM while sharing "real graphics hardware" across VM's on the host will enable all kinds of new applications to be virtualized.  You can read more on it @ RemoteFX.

Dynamic Memory (DM) is a new feature that will allows greater consolidation of VM's.  DM will aide VM consolidation by allowing physical host memory to be shared between VM's.  While the total memory used across VM's can appear to exceed total host physical memory it is actually in one of two categories - "free - ie its all zeros" or "physcial- meaning it is backed by a host physical page".  So how is this different from what Hyper-V could do before?  In previous versions of Hyper-V (Windows Server 2008 (SP1 / SP2 / R2) you have to statically set the amount of memory a VM would use before you start it.  For example you might set 2GB for a Server VM.  Now with Dynamic memory you get to set an initial value like 1GB and a maximum of 4GB.  As more VM's run on a host Hyper-V will look to see which VM's are most memory contrained and "borrow" memory from one VM's to give to another.  From the perspective of the VM it just looks like the System is using more memory where in fact the memory the system is reporting as used is no long backed by phsical memory in the host.  It is just a holding place.  At some future point I might go into more on how DM actually works and some of its balancing goals however today was you to let you know it is out there.  You can also read more @ Hyper-V Dynamic Memory Evaluation Guide

So where can you get these new features?  These new features are available in Windows Server R2 SP1 and Windows7 SP1.  Today you can only download the RC (http://technet.microsoft.com/en-us/evalcenter/ff183870.aspx) however keep a look out for the final release of SP1.


     Tony Voellm