If you’re keeping up with the latest release of Windows Server, Windows Server 2016 brings some interesting new features to the table. One particular item caught my eye: multi-domain and workgroup clusters. Does it work? Can I use it on the free Hyper-V Core? Let’s check it out.
What Makes It Work
I’ve managed many Windows failover clusters for SQL from 2003 up to 2012, and there’s always been a long-standing requirement that nodes must be joined to the same domain. That’s great… but this is my home office, I don’t have a domain.
This MSDN blog post covers 2016’s newfound ability to create a failover cluster without Active Directory dependencies, in addition to the pre-requisites for multi-domain or workgroup clusters.
One of the core requirements is setting a primary DNS suffix on each cluster node. Additionally, when creating the cluster, the AdministrativeAccessPoint type is DNS rather than ActiveDirectory. This, combined with excessive HOSTS-filing, and a couple of security tweaks, comprises the bulk of what’s different in a Workgroup cluster. If only it was that easy.
When To Use It
It’s worth stating up-front, after going through this exercise, if you’re already in a domain environment, use it. This might be a handy feature if you’re a small office without Active Directory but you require some local, resilient server infrastructure; otherwise, management can get a little complicated.
My reason for wanting a Workgroup cluster: home lab. I don’t run Active Directory domain services on my home network because I have a lot of devices passing through, and simplicity is important. DHCP, for instance, is served by my router. My NAS uses local user-based authentication. Rather than risk pissing off my family, I’d prefer to have a completely isolated lab, providing its own DHCP, DNS, and AD services. Creating a Workgroup-joined cluster running Hyper-V lets me put cluster nodes online without needing to expose AD to my home network to authenticate them, while benefiting from failover capabillities I don’t currently have in my single Hyper-V server (just Windows 10 with Hyper-V feature installed).
Can It Run On Hyper-V Core?
I’ll answer a question I asked myself, to which I never found the answer — yes, workgroup clusters do work on Hyper-V Core 2016. All of the documentation from Microsoft only explicitly mentioned Windows Server 2016, and although Hyper-V Core is just stripped-down Windows Server, there are differences and limitations. You will have an easier time doing this with full Windows Server, since you get a GUI, but we can get the job done in Powershell.
What Doesn’t Work
Per the Microsoft blog post I referenced above, looking under “Workload” although Hyper-V will run, and is supported, Microsoft doesn’t recommend it. Other applications like SQL are fully supported, and others like MSMQ are not at all supported.
The main reason for Hyper-V not being recommended is Live Migration – Hyper-V Workgroup Clusters cannot perform a Live Migration. Best I can tell, this is due to the authentication methods that back live migration. That being said, Quick Migration is supported and I can say it works great!
In Part 2 I’ll lay out my physical lab environment. It’s worth mentioning, if you’re just goofing around to see it work, you can do this inside an existing Hyper-V environment just to see it work – no hardware required.