We’re getting close to the release of Windows Server 2016 (looking at early next year) and currently, we’re on the third iteration of the technical preview.
One thing of note is that Microsoft is still working toward closing the gap between Hyper-V and VMware, as it has been over the last few years, and Windows Server 2016 is just another step in that direction with a few big new features.
Rolling Hyper-V Cluster Upgrades
One of the things that most people don’t know about Hyper-V is that until now, there’s been no in-place cluster upgrade options. A host had to be built/rebuilt, a new cluster had to be created, and then from there all the VMs had to be manually and painstakingly moved to the new cluster. It was very cumbersome and time consuming.
Now, there are functional levels for failover clusters such that a new 2016 server can be added into the existing cluster and it will operate as if it’s a 2012 R2 server until all servers are upgraded, and then the functional level can be upgraded. This is very much like how Active Directory functional levels work.
Microsoft calls snapshots “checkpoints.” This new checkpoint method being introduced will do a VSS-based snapshot inside the guest OS. This is so that if you revert to a snapshot, the state of the VM is healthy and happy. It triggers the entire VSS stack and the VM will be in a healthy state. This is NOT the same as VMware’s snapshot guest RAM; what that does is copy the entire state of the RAM of the server, so that if you revert, the server thinks it has traveled back in time rather than simply be in a healthy state at the current time.
Hot Add and Remove for Network Adapters and Memory
Adding and removing NICs on the fly is nothing new in the VMware world, and this is simply Microsoft catching up.
Adding memory to a VM while it’s running isn’t commonly used in VMware, but is a feature that can be leveraged. With this new feature of Hyper-V 2016, memory can not only be hot added to a VM, but hot REMOVED from a VM. So, if a server was set up with too much memory but a downtime can’t be accommodated to change its RAM, it can be removed “on the fly” as needed, which is a feature VMware does not support.
Integration Services Distributed Through Windows Updates
Integration services are the Hyper-V equivalency of VMware tools, which makes this seem rather uneventful, but can actually be a pretty useful feature in bigger environments with hundreds of VMs. Using VMware’s GUI to right click each VM and update the tools is way too tedious, but scheduling it to automatically upgrade them all can also be a bit scary if it requires restarts. Managing the integration services updates just like normal Windows updates with WSUS or SCCM is much easier and more familiar.
Windows PowerShell Direct
Administrators can now run PowerShell scripts directly inside a guest OS from the Hyper-V host using PowerShell Direct. This could be very useful for people needing to run a lot of scripts on several different VMs that are perhaps headless (Windows Server Core)… and it can be terrifying. As long as the user has administrative rights on the host and administrative rights on the guest OS, this allows or a lot of power over the guest without every directly logging in. It makes establishing proper permissions that aren’t pervasive much more important than they may have been before to prevent an unwitting admin from doing catastrophic damage.