Prism: Providing Flexible and Fast Filesystem Cloning Service for Virtual Servers

摘要

This paper describes a prototype virtualized file system, Prism, for supporting hosted servers and utility computing. Prism provides a filesystem service that allows lightweight creation of filesystems for new users from existing filesystems. All users' filesystems are mutable and yet isolated from each other. In our experiments, new filesystems can be created from existing ones in under one-fifth of a second. Prism is also designed to make centralized security-related services across multiple, similar filesystems more efficient. In particular, with Prism, tasks such as virus checking over multiple filesystem clones are much more efficient than scanning each user's filesystem independently. We describe the design of Prism and present performance results.