Documentation

Last week I registered in Eucalyptus' forum and immediately posted a question inquiring about the purpose of each controller in Eucalyptus. As I said then, it seems to me that there is a lack of clear and complete documentation about the system (mostly, regarding design and architecture), and as a consequence, many people are going through the motions of following tutorials and installation guides without really understanding the system at hand.

Somebody suggested reading the paper The Eucalyptus Open-source Cloud-computing System - which I had already read - to learn about the controllers. One problem with that paper is that it was written when Eucalyptus had no Storage Controller component besides Walrus. Therefore, there is no explanation about the purpose of the Storage Controller that has to exist now in every cluster running Eucalyptus. Additional note: that paper made back then an unfortunate use of the term storage controller to refer to Walrus, what contributes to the confusion.

Somebody also replied to my post providing a link to a discussion about the nature and purpose of Walrus and the Storage Controller. That helped to clarify the situation. However, I still think that Eucalyptus' documentation requires a lot of work if people are to start using the system.