The final component of the NAStore system is the DMFS system. This consists of dmfsd, the DMFS data migration daemon, system utilities to assist file migration, and the DMFS file system (the focus of this paper). dmfsd is the data migration daemon, and it runs on each host supporting a DMFS file system. It is responsible for responding to requests from the DMFS file system for file restoration. The userland system utilities in the DMFS system are responsible for archiving files and for making them non-resident. There are also utilities to permit users to force the archival or restoration of specific files.