This article series will walk you through the process of setting up a failover cluster for Hyper-V.
Over the last several years, server virtualization technology has completely transformed IT. In spite of all that this remarkable technology has accomplished, there has always been one major disadvantage to server virtualization. To put it bluntly, virtualized environments raise the stakes on hardware failure.
Think about it for a moment. In a non-virtualized environment, if a server experienced a catastrophic hardware failure it would most likely be an inconvenience. Sure, it would be important to promptly fix the problem, but the failure of a single server probably wouldn’t bring an organization’s business to a grinding halt. Even if the failed server was running a mission critical application, the end users would at least be able to access other network resources such as E-mail, file shares, and other applications while the problem is being fixed.
Virtual servers play by different rules though. Multiple virtual servers typically reside on a single host machine. As such, if the host were to experience a hardware failure then the end result would be equivalent to the failure of multiple machines in a non-virtualized environment.
Of course the perils of hosting multiple VMs on a single server can sometimes come into play even if a hardware failure has not occurred. For example, I recently heard of someone who was running twelve virtual machines on a single host server. The administrator decided that the host server needed more memory, but discovered that scheduling a time in which all twelve virtual machines could be taken off line at the same time so that the necessary memory could be installed was a major issue.
Thankfully, Microsoft has designed Windows Server 2008 R2 in a way that allows Hyper-V to reside within a failover cluster. Failover clustering for Hyper-V can help to address all of the issues that I have described so far.
Best of all, a new feature called Live Migration makes it possible to move virtual machines between cluster nodes without taking the virtual machine offline. That way, if you need to take a host server offline for maintenance, you can simply move all of the virtual machines to a different cluster node and perform the necessary maintenance without having to schedule any down time.
Even though Windows Server 2008 R2 has been around for a while, I have to confess that until recently I had never gotten the chance to experiment with failover clustering for Hyper-V or with the Live Migration feature. Recently though, one of my clients asked me to implement failover clustering for them so that they could take advantage of Live Migration. In doing so, I discovered that even though the setup and configuration process is relatively straightforward, there are a few gotchas. I also found that there are several tutorials on the Internet that are either inaccurate or incomplete. As such, I wanted to write this article series as a way of providing the IT community with an easy to follow guide to the configuration process.
- Setting Up Failover Clustering for Hyper-V (Part 1)
- Setting Up Failover Clustering for Hyper-V (Part 2)
- Setting Up Failover Clustering for Hyper-V (Part 3)
- Setting Up Failover Clustering for Hyper-V (Part 4)