Network assisted file system consistency checking

Abstract

This thesis reports on the design and implementation of Network Assisted NFSCK (or NAN), an extension to NFSCK, a research project about checking file system consistency at NetApp. NFSCK requires disk space to store temporary files, but sometimes insufficient disk space is available, and NFSCK cannot be used. NAN allows NFSCK to use an NFS server to store these temporary files. Tests were run to compare the total running time of NAN and NFSCK on various machines and data sets. Results showed that CPU was the limiting factor for NAN's performance. On machines with four CPUs, the running time of NAN was within 1% of the running time of NFSCK. On machines with two CPUs, running time was up to 6% worse with a large file data set, and up to 22% worse with a small file data set.