Marc M. Eshel

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.

Multimedia file serving with the OS/390 LAN server

The rapidly increasing storage and transmission capacities of computers and the progress in compression algorithms make it possible to build multimedia applications that include audio and video. Such applications range from educational and training videos, delivered to desktops in schools and enterprises, to entertainment services at home. Applications developed for stand-alone personal computers can be deployed in distributed systems without change by using the client/server model and file servers that allow the sharing of applications among many users. The OS/390™ LAN Server has been enhanced to support multimedia data delivery. Resource management and admission control, wide disk striping to provide high data bandwidths, and multimedia-specific performance enhancements have been added. The resulting server benefits from the robustness, scalability, and flexibility of the S/390® system environment, which allows it to move into new multimedia applications. Multimedia support on a robust, widely installed platform with little or no additional hardware requirements gives customers the opportunity to enhance their existing applications with multimedia features and then expand their capacity as the demands of the applications increase. This multimedia server platform is in use with several interesting applications.