"Sheepdog is a new third party open source project around kvm providing distributed storage management features. Sheepdog provides high availability to kvm guests by providing block level storage volumes to virtual machines similar to Amazon EBS (Elastic Block Storage). In fact one of the items on the sheepdog project todo list is to support the Amazon EBS API. Sheepdog is designed to scale to hundreds of nodes. You can think of this technique as striping your virtual disk data across multiple nodes similar to what raid does. The project is still very early in its development cycle but already provides basic functionality."