A multiple-file write scheme for improving write performance of small files in Fast File System

Fast File System (FFS) stores files to disk in separate disk writes, each of which incurs a disk positioning (seek + rotation) limiting the write performance for small files. We propose a new scheme called co-writing to accelerate small file writes in FFS without sacrificing its advantages. The scheme collects writes to small files in the same directory and stores them together to disk in a single large disk write. Co-writing multiple files in one disk I/O can reduce disk positioning times resulting from small file writes in FFS. Our experiments on OpenBSD show that the co-writing slashes the cost of small file writes in FFS by up to 33%, in both real-world and synthetic benchmarks.