One of the most highly anticipated new features in Windows Server 2008 R2 Hyper-V is its live migration feature. With Hyper-V live migration, you can move running VMs from one Hyper-V physical host server to another without any disruption of service or perceived downtime. This is Microsoft's answer to VMware VMotion.
Microsoft's virtualization adoption should get a major push in the market just with the addition of this one feature. Why is that?
Microsoft may have downplayed the importance of VMware's VMotion technology when it first launched Hyper-V, saying that its quick migration feature was adequate enough for what most people needed. But I don't think virtualization administrators as a whole bought into that theory, and I doubt Microsoft truly believed it either, to be honest.
With that, I think the lack of a VMware VMotion-like technology in Microsoft's Hyper-V offering really gave people pause from incorporating the solution into their production environments. But now, with the addition of live migration, I'm fairly certain that we'll see a larger adoption toward Hyper-V. Whether someone actually uses this feature or not, people expect it in an enterprise, production-class server virtualization platform.
So because Hyper-V live migration can move running virtual machines without any downtime, it facilitates greater flexibility and value. The newly added feature:
- Provides better agility: Datacenters with multiple Hyper-V physical hosts will be able to move running VMs to the best physical computer for performance, scaling, or optimal consolidation without impacting users.
- Reduces costs and increase productivity: Datacenters with multiple Hyper-V physical hosts will be able to service those systems in a more controlled fashion, scheduling maintenance during regular business hours. Live migration makes it possible to keep VMs online, even during maintenance windows, increasing productivity for both users and server administrators. Datacenters will be also able to reduce power consumption by dynamically increasing consolidation ratios and powering off unused physical hosts during times of lower demand.
To help get you ready for this added feature, Microsoft has created a document that describes the live migration feature of Windows Server 2008 R2 Hyper-V in detail, and it includes information on how live migration moves running VMs, describes several scenarios where live migration is particularly useful, and lists the requirements for implementing live migration.
If you are planning to roll out this new technology, you definitely want to check out this Hyper-V live migration overview and architecture document.
And at the same time, you should probably check out Microsoft's Step-by-Step Guide to Using Live Migration in Windows Server 2008 R2. The guide details the steps required to perform a live migration of Hyper-V virtual machines from one node in a Windows Server 2008 R2 failover cluster to another node.