I installed Ubuntu Eucalyptus cloud (#UEC) on a couple of servers at home. I was naively expecting it to be similar to VMware. Oh I was wrong.
UEC is the Eucalyptus ‘cloud’ software running on Ubuntu servers. The instances would run under the KVM or Xen hypervisors. Ubuntu’s defaulted to running KVM but isn’t restricted by it.
“Eucalyptus is a software available under GPL that helps in creating and managing a private or even a publicly accessible cloud. It provides an EC2 compatible cloud computing platform and S3 compatible cloud storage platform…” Eucalyptus Beginner’s Guide
This is how a vm works in UEC:
You publish an image that you previously installed all the software you need (or you can download such an image). There can be as many instances of this image running as the hardware supports (spread across N number of backend Node Servers).
All instances are transient. As long as an image is running, it will have a physical presence.. but when it is shutdown, the instance is removed including any work performed in the instance.
“static” storage is available via a Storage Server. After you create an image but before you start it, you have the opportunity to attach storage to the instance.
While the management tools for UEC, and therefore Amazon EC2/EM, are primitive compared to VMware, it should be able to scale much higher with far less focus on which ‘virtual machine’ goes where.