“…Parallel file systems, such as Lustre (Lustre 2.0 Operations Manual), GPFS (Schmuck and Haskin, 2002), PanFS (Welch et al, 2008), and PVFS/PVFS2 (Carns et al), enable concurrent I/O accesses from multiple clients to files. Numerous optimizations also exist that improve the file system performance, such as data staging services (Abbasi et al, 2011), coordinated access interface (Lang et al, 2009), performance bridging (Gu et al, 2008), a log-structured interposition layer, and latent asynchrony I/O (Widener et al, 2011). While parallel file systems perform well for large and well-formed data streams, however, they often perform inadequately when dealing with many small and noncontiguous data requests.…”