Recently, I have been working on a piece of technology that enables full and incremental backups of running VMs. My first implementation is for KVM. It is, by design, very low overhead technology. It does not impose the cost of continuous synchronization such as drbd does. Yet it offers a solution that should work for a substantial number of VMs.
I have been involved in discussions with the KVM community to get this software into the main kvm codebase. Towards this end, I presented LiveBackup to the KVM community at the KVM forum 2011. Here is a link to the KVM forum 2011 agenda.
And here is a link to the slides for my presentation.
Most presentations were recorded, and I will post a link when the recordings become available.