GPFS: A Shared-Disk File System for Large Computing Clusters

Abstract

GPFS is IBM’s parallel, shared-disk file system for cluster computers, available on the RS/6000 SP parallel supercomputer and on Linux clusters. GPFS is used on many of the largest supercomputers in the world. GPFS was built on many of the ideas that were developed in the academic community over the last several years, particularly distributed locking and recovery technology. To date it has been a matter of conjecture how well these ideas scale. We have had the opportunity to test those limits in the context of a product that runs on the largest systems in existence. While in many cases existing ideas scaled well, new approaches were necessary in many key areas. This paper describes GPFS, and discusses how distributed locking and recovery techniques were extended to scale to large clusters.

Link to the full paper:
http://www.almaden.ibm.com/StorageSystems/projects/gpfs/Fast02.pdf

Presented by Prudhvi Reddy Avula
Link to the slides:
http://www.cse.buffalo.edu/faculty/tkosar/cse726/slides/01-avula.pdf


Review #1 by Venkata Sudheerkumar Mupparaju 
This paper “GPFS: A Shared-Disk File System for Large Computing Cluster” describes the overall architecture of GPFS (General Parallel File System) which is IBM's parallel shared-disk file system for cluster computers, paper describes its approach to achieving parallelism and data consistency in cluster environment, it details some of the features that contribute to its performance and scalability, describes the design for fault-tolerance and presents data on its performance.

GPFS achieves its extreme scalability through its shared-disk architecture. SAN provides Shared Disks, but SAN itself does not provide a Shared File System. If you have several computers that have access to a Shared Disk and try to use that disk with a regular File System, the disk logical structure will be damaged very quickly. Disk Space Allocation inconsistency and File Data inconsistency makes it impossible to use Shared Disks with regular File Systems as Shared File Systems. Cluster File Systems are designed to solve the problems outlined above. GPFS is one such parallel File System for cluster computers that provides as closely as possible the behavior of a general- purpose POSIX file system running on a single machine...

Link to the full review: 
http://www.cse.buffalo.edu/faculty/tkosar/cse726/reviews/01-review1-mupparaju.pdf


Review #2 by Pramod Kundapur Nayak

With the thirst for higher computing power in demand, cluster computing has become a trend. Fault-tolerance, boundless computing power, unrestrained storage capacity being prime requirements of a reliable system, cluster computing has been of keen interest among researchers. This paper focuses on the storage aspect of cluster computing by introducing GPFS (General Parallel File System), a file system package from IBM, which provides functionalities similar to standard POSIX file system.

To summarize:

• GPFS appears to work like traditional POSIX file system but provides parallel access to files.
• Enhanced performance achieved through data striping at block level across all disks in file system.
• Supports upto 4096 disks of upto 1TB each, providing a total of 4 petabytes per file system.
• Both file data and metadata of any disk is accessible from any node through disk I/O calls. Further, GPFS facilitates parallel flow of both data and metadata from node to disk.
• Highly reliable with fault-tolerance and replication mechanism.

This paper highlights GPFS’s answers to performance, scalability, concurrency and fault- tolerance issues of large file system and provides bird’s eye view of GPFS...

Link to the full review:
http://www.cse.buffalo.edu/faculty/tkosar/cse726/reviews/01-review2-nayak.pdf