Performance Measurement of the Concurrent File System of the Intel iPSC/2 Hypercube

Abstract The Intel Concurrent File System (CFS) for the iPSC/2 and iPSC/860 hypercubes is one of the first production file systems to utilize the declustering of large files across numbers of disks to improve input/output (I/O) performance. The CFS also makes use of dedicated I/O nodes, operating asynchronously, which provide file caching and prefetching. Processing of I/O requests is distributed between the compute node that initiates the request and the I/O nodes that service the request. We present performance measurements of the CFS for an iPSC/2 hypercube with 32 compute nodes and 4 I/O nodes (4 disks). Measurement of read/write rates for one compute node to one I/O node, one compute node to multiple I/O nodes, and multiple compute nodes to multiple I/O nodes form the basis for the study. Additional measurements show the effects of different buffer sizes, caching, prefetching, and file preallocation on system performance. A measure of I/O system imbalance is also introduced.