Delta compression, which consists of compactly encoding one le version as the result of changes to another, can improve eciency in the use of network and disk resources. Delta compression techniques are readily available and can result in compression factors of ve to ten on typical data. Managing delta-compressed storage, however, is a dicult task. I will present a system that attempts to isolate the complexity of delta-compressed storage management by separating the task of version labeling from performance issues. I will show how the system integrates delta-compressed transport with delta-compressed storage. Existing tools for managing delta-compressed storage suer from weak le system support. Lack of transaction support is responsible for inecient application behavior. The only atomic operation in the traditional le system forces unnecessary disk activity due to copying costs. I will demonstrate that transaction support can improve application performance and extensibility wit...

This paper presents MVSS, a storage system for active storage devices. MVSS oers a single framework for supporting various services at the device level. It provides a exible interface for associating services to a le through multiple views of the le. Similar to views of a database in a multi-view database system, views in MVSS are generated dynamically and are not stored on physical storage devices. MVSS represents each view of an underlying le through a separate entry in the le system namespace. MVSS separates the deployment of services from le system implementations and thus allows services to be migrated to the storage devices. The paper presents the design of MVSS and how dierent services can be supported in MVSS at the device level. To illustrate our approach, we implemented a prototype system on PCs running Linux. We present results from the prototype implementation to demonstrate the eectiveness of our approach. 1

MVSS is a storage system that oers a single framework for supporting a wide range of proposed new services. MVSS proposes to provide a exible interface for associating services to a le through multiple views of the le. Multiple views of a le in MVSS are similar to views of a database in a multi-view database system. Multiple views of a le in MVSS are generated dynamically and are not stored on the physical storage device. MVSS represents each view of the underlying le through a separate entry in the le system namespace. Relative to approaches that provide services through namespace such as stackable le systems, MVSS separates the deployment of services from le system implementations and thus allows services to be performed at various levels of the storage system. This paper shows the design of MVSS and how various services such as encryption, networkattachment and application-level intelligence can be supported in MVSS at the device level. To illustrate our approach...

Introduction In traditional storage systems, physical device geometry information are exposed to le systems. File system can obtain the physical address of logical disk blocks, and utilize this knowledge to improve data layout locality [1]. Nowadays, the storage technology are making this picture more and more impractical. Storage devices are getting more and more complex(for example, RAID), so the simple geometry model may no longer apply. The emerging network-attached storage makes optimization in le system less useful, for the storage is no longer local. With these trends, a virtualized storage interface can be more valuable, where the storage system, working like virtual memory, exports virtual address and transparently translates every access into physical device address. Opportunities enabled by this virtual address translation are: Global optimization. Optimizations like load balancing, data replication can be done in the storage system. <F1