NPAC Technical Report SCCS-420

An Experimental Performance Evaluation of Touchstone Delta Concurrent File System

Rajesh Bordawekar, Alok Choudhary, JuanMiguel delRosario

Submitted December 07 1992


Abstract

For a high-performance parallel machine to be truly a scalable system, it must have a scalable parallel I/O system. recently, several commercial machines (e.g. Intel Touchstone Delta, Paragon, CM-5, Ncube-2) have been built that provide features for parallel I/O. However, very little is understood about the performance of these I/O systems. This paper presents an experimental evaluation of the Intel Touchstone Delta's Concurrent File System (CFS). The CFS utilizes the declustering of large files across the disks to improve the I/O performance. Data files can be read or written on the CFS using 4 access modes. The disks on which data is stored can be varied from 1 to 64. We present performance measurements for the CFS on the Touchstone Delta with 512 compute nodes and 32 I/O nodes. The study focuses on file read/write rates for various configurations of I/O and compute nodes. The study attempts to show the effect of access modes,buffer sizes and volume restrictions on system performance. The paper also shows that the performance of the CFS can greatly vary for various data distributions commonly employed in scientific and engineering applications.


PostScript version of the paper