Parallel I/O subsystems in massively parallel supercomputers

Abstract

Applications executing on massively parallel processors (MPPs) often require a high aggregate bandwidth of lowlatency I/O to secondary storage. In many current MPPs, this requirement has been met by supplying internal parallel I/O subsystems that serve as staging areas for data. Typically, the parallel I/O subsystem is composed of I/O nodes that are linked to the same interconnection network that connects the compute nodes. The I/O nodes each manage their own set of disks. The option of increasing the number of I/O nodes together with the number of compute nodes and with the interconnection network allows for a balanced architecture. We explore the issues motivating the selection of this architecture for secondary storage in MPPs. We survey the designs of some recent and current parallel I/O subsystems, and discuss issues of system configuration, reliability, and file systems.