Frank B. Schmuck

The Tiger Shark file system

Tiger Shark is a parallel file system for IBMs AIX operating system. It is designed to support interactive multimedia, particularly large-scale systems such as interactive television (ITV). Tiger Shark scales across the entire RS/6000 product line, from small desktop machines to the SP-2 parallel supercomputer. Tiger Sharks primary features are support for continuous time data, scalability, high availability, and manageability, all of which are crucial in its role in large-scale video servers. Interestingly, most of the features that make Tiger Shark a good video server are important for other large-scale applications such as technical computing, data mining, digital library, and scalable network file servers. This paper briefly describes Tiger Shark: the environment that makes it important, the key technology it embodies, and the efforts to build products based on it.

Experience with transactions in QuickSilver

All programs in the QuickSilver distributed system behave atomically with respect to their updates to permanent data. Operating system support for transactions provides the framework required to support this, as well as a mechanism that unifies reclamation of resources after failures or normal process termination. This paper evaluates the use of transactions for these purposes in a general purpose operating system and presents some of the lessons learned from our experience with a complete running system based on transactions. Examples of how transactions are used in QuickSilver and measurements of their use demonstrate that the transaction mechanism provides an efficient and powerful means for solving many of the problems introduced by operating system extensibility and distribution.

Panache: a parallel WAN cache for clustered filesystems

Panache is a scalable, high-performance, remote file data caching solution integrated with the GPFS cluster file system. It leverages the inherent scalability of GPFS to provide a multi-node, consistent cache of data exported by a remote file system cluster. Panache exploits the soon-to-be standard pNFS protocol to move data in parallel from the remote file cluster. Furthermore, it provides a POSIX compliant file system interface making the cache completely transparent to applications. Panache can mask the fluctuating wide-area-network latencies and outages by supporting asynchronous and disconnected-mode operations. It allows concurrent updates to be made at the cache and at the remote cluster and synchronizes them by using conflict detection techniques to flag and handle conflicts. To maintain commercial viability, Panache relies on open standards for high-performance file serving and does not require any proprietary hardware or software to be deployed at the remote cluster. In this paper we present the overall architecture of Panache and its key features.