This paper describes a new version of the Network File System (NFS) that supports access to files larger than 4GB and increases sequential write throughput sevenfold when compared to unaccelerated NFS Version 2. NFS Version 3 maintains the stateless server design and simple crash recovery of NFS Version 2, and the philosophy of building a distributed file service from cooperating protocols. We describe the protocol and its implementation, and provide initial performance measurements. We then describe the implementation effort. Finally, we contrast this work with other distributed file systems and discuss future revisions of NFS. 1.

To meet enterprise and grand challenge-scale performance and interoperability requirements, a group of engineers—initially ad-hoc but now integrated into the IETF—is designing extensions to NFSv4 that provide parallel access to storage systems. This paper gives an overview of pNFS, an emerging NFSv4 extension that promises file access scalability plus operating system and storage system independence. pNFS bypasses the server bottleneck by enabling direct access to storage by NFSv4 clients and by providing a framework for the co-existence of NFSv4 with other file access protocols. In this paper, we describe an implementation that demonstrates and validates pNFS ’ potential. The I/O throughput of our prototype matches that of its exported file system and far exceeds standard NFSv4.

NFS is a widely used remote file access protocol that has been tuned to perform well on traditional LANs which exhibit low error rates. Users migrating to mobile hosts would like continued remote file access via NFS. However, low bandwidth and high error rates degrade performance on mobile hosts using wireless links, hindering the use of NFS. This paper presents two mechanisms which improve NFS performance over wireless links: an aggressive NFS client and link-level retransmissions. Our experiments show that these mechanisms improve response time by up to 62%, which brings the performance to within 5% of that obtained in zero error conditions. 1 Introduction Mobile computing is increasingly in demand and will be an important part of the computing infrastructure in the near future. The use of wireless links gives the mobile user new freedom and flexibility. Unfortunately, since most applications and reliable transport protocols have been optimized for wired networks and static hosts, t...

There is a definite trend in the Enterprise Storage industry to move from Network Attached Storage (NAS) solutions to high performance Storage Area Networks (SANs). This paper describes a file system design that can leverage existing NAS infrastructure along with evolving SAN technology to provide high performance storage access while reducing the cost of migrating to these networks.

Unix’s lack of a robust and expandable file system has become a significant problem with the growth of UNIX in large commercial environments. The HAMFS (Highly Available Multi-server File System) is a cluster file system designed to address this need. HAMFS offers disk-pooling, supports off-the-shelf disks, and automatically balances file load across disks dynamically. Data residing in a disk pool is directly accessible from every node in a HAMFS cluster. As user’s capacity requirements grow, HAMFS provides easy disk pool expansion. Finally, HAMFS provides uniform scaling of file system performance from a single node configuration to large multi-node clusters, offering significant performance advantage over traditional file systems. For example, in short file access situations, HAMFS provide a factor of five performance improvement over NFS, and a factor of two improvement over conventional local file systems. Technologies developed for HAMFS are applied to Fujitsu’s file system product SafeFILE. 1.

: In most modern local area network environments, NFS is used to provide remote file storage on a particular server machine. A consequence of this distributed architecture is that the failure of the server results in paralysis or a loss of work for users. This paper presents the design of a low-cost fault tolerant NFS server which can be installed on most Unix networking environments. FT-NFS runs as a user process and does not necessitate any underlying specific operating system functionality. The originality of our approach relies on the use of a stable cache which provides data availability and resiliency to a single failure. The main benefits of the stable cache are first to allow disk write operations to be safely performed in the background and second to permit the gathering of small files in large containers. The latter technique permits disk I/Os to be improved by reducing their number and increasing their length. Under the nhfsstone benchmark, FT-NFS outperforms the in-kernel S...

A Systematic Characterization of Application Sensitivity to Network Performance by Richard Paul Martin Doctor of Philosophy in Computer Science University of California at Berkeley Professor David E. Culler, Chair This thesis provides a systematic study of application sensitivity to network performance. Our aim is to investigate the impact of communication performance on real applications. Using the LogGP model as an abstract framework, we set out to understand which aspects of communication performance are most important. The focus of our investigation thus centers on a quantification of the sensitivityof applications to the parameters of the LogGP model: network latency, software overhead, per-message and per-byte bandwidth. We define sensitivity as the change in some application performance metric, such as run time or updates per second, as a function of the LogGP parameters. The strong association of the LogGP model with real machine components allows us to draw architectural conclusions from the measured sensitivity curves as well.