Virtual Appliances for Deploying and Maintaining Software

This paper attempts to address the complexity of system administration by making the labor of applying software updates independent of the number of computers on which the software is run. Complete networks of machines are packaged up as data; we refer to them as virtual appliances. The publisher of an appliance controls the software installed on the appliance, from the operating system to the applications, and is responsible for keeping the appliance up to date. These appliances can be configured by users to fit their needs; the configuration is captured such that it can be reapplied automatically when the appliance's software is updated. We have developed a compute utility, called the Collective, which assigns virtual appliances to hardware dynamically and automatically. By keeping software up to date, our approach prevents security break-ins due to fixed vulnerabilities.This paper presents the concept of virtual networks of virtual appliances and describes our prototype of the Collective Utility. We demonstrate the feasibility of our approach by creating appliances for groupware servers, Windows desktop environments, and software development environments.