Monthly Archives: June 2008

Xen Summit Highlights – Cloud Computing

Andres Lagar-Cavilla from the University of Toronto presented a unique methodology to create “instant” DomUs within a cloud on demand. His project, Snowflock, is detailed below:

Snowflock is our prototype implementation of the Impromptu Cluster (IC) abstraction. In an IC, an application encapsulated inside a virtual machine (VM) is swiftly forked into multiple copies that execute on different physical hosts, and then disappear when the computation ends. ICs simplify the development of parallel applications and reduces management burden by enabling the instantiation of new stateful computing elements: workers that need no setup time because they have a memory of the application state achieved up to the point of forking. This approach combines the benefits of cluster-based parallelism with those of running inside a VM.

Snowflock provides swift parallel VM cloning that makes it possible for Internet applications to deliver near-interactive performance for resource-intensive highly-parallelizable tasks. Snowflock makes use of four key techniques: VM descriptors (condensed VM images that allow for sub-second suspension of a running VM and resumption of a of replicas); a memory-on-demand subsystem that lazily populates the VM’s memory image during runtime; a set of avoidance heuristics that minimize the amount of VM memory state to be fetched on demand; and a multicast distribution system for commodity Ethernet networking hardware that makes the overhead of instantiating multiple VMs similar to that of instantiating a single one.

He has created a site that anyone interested in learning more can register at: His presentation at Xen Summit is here.

Xen Summit Boston Page Live

I have updated the site and created a new Xen Summit Boston page:

I am still collecting presentation slides and converting them to pdf so not everything is live yet. I will also be adding the videos of the presentations shortly but I need a bit more bandwitdh to make that happen so that will update over time.

Also, check out the cool new logo for the Xen Summit Tokyo (Asia) sponosored by Fujitsu on the main Xen Summit page.

Xen Summit Highlights

Over the next few days I will be putting out highlights from this year’s Xen Summit in Boston. Many interesting projects, concepts, and “Xen deployments” were presented and I want to share some of these with you. I will also be setting up a new page on that contains a list of active Xen development projects to better allow the community to find interesting work to spend your time on.

I want to start my Xen Summit commentary by promoting the Samsung announcement of their release into Open Source of the Xen port for the ARM processor. The project is now live and actively being tracked at and there is a xen-arm mailing list also available. I will be posting the presentation from Samsung along with the video which includes a great demonstration of moving a DomU from one prototype mobile device to another later today so be sure to check back to the Xen Summit tab on later today.