Does Hyper-V's Lack Of Live Migration Matter?

Microsoft on Monday said Hyper-V's oft-delayed Live Migration feature will be part of Windows Server 2008 R2 when it's released in 2010. While that might seem like a long time for Microsoft to add a feature that VMware has had since 2004, solution providers aren't concerned that Live Migration isn't part of the software giant's virtualization portfolio.

"Live Migration is not important to us at all at this point," said Rand Morimoto, president of Convergent Computing, an Oakland, Calif.-based solution provider and Microsoft Gold partner. "With what Microsoft offers out of the box today, I'm not sure whether we have a need for Live Migration."

Live migration, an enterprise-class feature included in the VMware and Xen-based virtualization platforms, makes it possible to move running virtual machines from one system to another system. Microsoft says a feature in Hyper-V called Quick Migration, which is almost as fast as live migration, can perform virtual machine migrations in just six seconds.

Jaymes Davis, virtualization practice manager at Entisys, a Concord, Calif.-based solution provider, says Quick Migration is sufficient for both planned and unplanned scenarios.

"I may experience an outage because I need to move a virtual machine, but because I have load balancing, I won't suffer any downtime as long as I have a cluster-aware application," Davis said.

"Live Migration is a great thing to have, and in Windows Server 2008 R2, it'll definitely be something the product needs," said Davis. "But right now, Quick Migration will suffice for companies' need to stabilize on a virtualization platform that saves them money and increases their business agility."

Morimoto notes that solution providers have other methods for ensuring high availability and disaster recovery for line of business applications, including leveraging the capabilities built into the apps themselves.

For example, SQL Server supports SQL Mirroring, a tactic that replicates database data across two or more servers in real time, and Exchange 2007 includes Cluster continuous replication (CCR), a feature that replicates mailboxes to different locations across a WAN.

For apps that don't have these features, Morimoto uses Hyper-V's failover clustering feature, which automatically funnels data to another host server that can restart guest images if the primary server goes down.

"In the environments where we're implementing Hyper-V, we have what we need today, and it's working great," said Morimoto.

Chris Ward, senior solutions architect at Greenpages, a solution provider in Kittery, Maine, says Live Migration has legit, real world uses that extend beyond enterprises and into the small business space.

"Granted, there are some small businesses who may not believe they need this type of 'advanced' technology, but we've put VMware's ESX enterprise into several of these very small accounts with only two physical hosts, and very cheap iSCSI shared storage, and they've found it incredibly useful," said Ward.

"Microsoft will say that the small businesses do not need these enterprise level features, which may be true, but if they can have them for a little more money, I think they'll bite," added Ward.