In his presentation at Build 2015 on Windows and Hyper-V Containers, Taylor Brown almost casually mentioned that in the next version of Windows Server, it will be possible to enable Hyper-V in a Hyper-V VM. The news was broken by fellow Hyper-V MVP Ronald Beekelaar who attended this great session in San Francisco.
Very quickly dozens of emails appeared in my mailbox from very enthusiastic fellow MVPs who have been begging for this feature for several years now. In fact I have also pleaded for nested hypervisor as we often have to build labs and prepare demos which include Windows Azure Pack. Some of its features can do without a Hyper-V server or cluster such as websites, databases, service management automation, but if VMM and infrastructure as a service is involved, we badly miss a Hyper-V host to deploy VM Roles. Of course we could add physical host to the lab, but with so many consultants in our CloudOS team, there just isn’t enough hardware.
Now that Microsoft has acknowledged that nested Hyper-V will be possible in a future build of vNext, it will be much easier for us to start learning the new Azure Pack and the many new features of Virtual Machines v2, equivalent to public Azure that is on the roadmap.
The real reason why Microsoft introduces running Hyper-V within Hyper-V is the anticipated new service to run Hyper-V Containers in Azure. Just like hypervisors abstract the operating system from the hardware, containers abstract the application from the operating system. There are two types of containers: Windows Server Containers and Hyper-V Containers. The former runs on the bare metal and the latter requires the Hyper-V hypervisor so that Containers can run in Hyper-V VMs. It stands to reason that Hyper-V Containers are much more suitable for Azure than giving customers access to the physical host, which would simply be impossible.
So expect to be running Hyper-V containers in an Azure VM (probably of the Nano Server type), running on the Azure fabric and once this is possible, you will also be able to run other guests inside an Azure VM. Because the same version of CloudOS will be available to public Azure, hosted Azure as well as private Azure, you can benefit from this new technology wherever it suits you best.
I can hardly wait for this new technology to become generally available!
If you want to see the session on Containers by Taylor Brown and Mathew John, take a look at the slides and recorded presentation: http://channel9.msdn.com/Events/Build/2015/2-704