Fujitsu FEFS

Fujitsu's own Lustre-based appliance, and the fact that Fugaku names it explicitly is useful in itself: most of this dataset's storage rows are inferred from a system's era rather than stated by the operator. RIKEN's own architecture page describes a three-layer hierarchy: LLIO, a node-local NVMe accelerator, absorbs each job's burst traffic; FEFS is the large shared area everyone's data actually lives in; commercial cloud storage sits behind both as a third tier. FEFS is also the continuity between Fugaku and its predecessor, K computer, which used the same Fujitsu product a decade earlier, so the file system a user sees changed far less across that transition than the processor did.