UNIX Filesystems: Evolution, Design, and Implementation

Summary

Throughout the history of UNIX, there have been numerous attempts to share files between one computer and the next. Early machines used simple UNIX commands with uucp being commonplace.

As local area networks started to appear and computers became much more widespread, a number of distributed filesystems started to appear. With its goals of simplicity and portability, NFS became the de facto standard for sharing filesystems within a UNIX system.

With the advent of shared data storage between multiple machines, the ability to provide a uniform view of the storage resulted in the need for clustered filesystem and volume management with a number of commercial and open source clustered filesystems appearing over the last several years.

Because both solutions address different problems, there is no great conflict between distributed and clustered filesystem. On the contrary, a clustered filesystem can easily be exported for use by NFS clients.

For further information on NFS, Brent Callaghan's book NFS Illustrated [CALL00] provides a detailed account of the various NFS protocols and infrastructure. For further information on the concepts that are applicable to clustered filesystems, Dilip Ranade's book Shared Data Clusters [RANA02] should be consulted.