R-CCS Cafe 第204回 第3部

The K computer employs the file staging method in which input files and output file are transferred between the local file system and the global file system before and after the job's execution. Since the staging operation can be overlapped with the job execution, this method mitigated the drawback of the global file system's throughput, but caused uncertain processing times on the staging-out phase if a huge number of files were copied.
Similar to the K computer, we decided to have a 1st-layer storage system for Fugaku, but the purpose of this storage system was examined by reflecting the file I/O usages in the target applications. Based on this review, we designed three types of file I/O services, local and shared file systems and cache for the global file system (2nd-layer storage), and decided those file I/O performances.