The sad, bad secret about cloud-computing is that setting up a cloud and running an application on any of them is relatively easy, managing it though, that's another thing entirely. That's where companies like Convirture come in.
Convirture's open-source project is ConVirt Open Source. With it you can manage both Xen and KVM (Kernel-based Virtual Machine)-based virtual machines (VM) and clouds. Specifically, with ConVirt, you can create and provision "gold" images, diagnose performance problems, and balance load across the datacenter, all from a Web-based interface and with consistent feature set across open-source virtualization platforms.
I've played with it some, and it works well. I especially liked that I could drag and drop live virtual machines between servers without interrupting their operations. This GPLed program allows you to re-allocate physical resources to virtual machines and balance the workload without incurring any downtime.
If you want to do more with it, Convirture has just announced a commercial product, ConVirt Enterprise Cloud. This, the company states, lets you manage private clouds, hybrid clouds and traditional virtualized infrastructure from a single Web console. With it you manage how datacenter resources are allocated between traditional enterprise applications, private clouds and public cloud resources such as Amazon EC2.
"Enterprise clouds are the natural next step in the evolution of the virtualized datacenter and IT staff should be able to manage cloud-based computing resources right along with existing virtual machines," said Arsalan Farooq, founder and CEO of Convirture in a statement. "Our customers are not interested in a 'rip-and-replace' approach, which leads to the separation of the infrastructure used to deliver cloud services from the rest of the virtualized environment. With ConVirt Enterprise Cloud, IT staff can build out a virtualized data center in the most flexible and cost-effective way. By managing traditional virtualized workloads side-by-side with cloud operations, ConVirt ensures a holistic view of the entire datacenter and allows IT staff to react quickly to changing business priorities."
From what I can see of it, this looks quite promising. I really like that it can give me management support for my local cloud, a remote datacenter private cloud, and public clouds like Amazon's offering. Speaking as someone who does a lot of networking work, I also like that I can choose to put a client on an existing corporate network, pre-configure Virtual LANs (VLANs) for them, or allow the cloud to create its own VLANs within a specified address range.
It also doesn't hurt that ConVirt Enterprise Cloud supports third-party private cloud infrastructure platforms such as Eucalyptus and OpenStack, so you can a centralized view of your virtualized datacenter. Since, at this point, there's no telling who's going to be the dominant cloud architecture, I like this flexibility.
So, in short, if you want to run a small cloud of Xen and KVM VMs, give ConVirt Open Source a try. If it works for you, and you need more, check out their commercial offerings. I think you might just like both.