Bigfoot-NFS : A Parallel File-Striping NFS Server ( Extended Abstract )

Bigfoot-NFS allows the transparent use of the aggregate space of multiple NFS file servers as a single file system. By presenting a single apparent file system to the user, Bigfoot-NFS allows the use of available storage without the maintenance overhead of tracking multiple mounted file systems. Unlike most other network parallel file systems, Bigfoot-NFS runs without a central “metadata” server that binds a file to its location. Bigfoot-NFS uses vectored remote procedure calls to get reasonable performance with multiple servers while retaining the simplicity of stateless NFS semantics. To date, we have demonstrated Bigfoot-NFS file systems as large as 30 gigabytes spanning 28 nodes. The server currently runs as a user-level process under SunOS. Because of context-switching overhead, Bigfoot-NFS generally runs 2-3x slower than the kernel based implementation of NFS. However, measurements of Bigfoot-NFS show that many file operations still show reasonable performance with increasing numbers of servers, and demonstrate how parallel file systems can be designed without centralized metadata servers.