.\" Copyright (c) 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" This document is derived from software contributed to Berkeley by .\" Rick Macklem at The University of Guelph. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .(l C .sz 14 .b "The 4.4BSD NFS Implementation" .sp .sz 10 Rick Macklem .i "University of Guelph" .)l .sp 2 .ce 1 .sz 12 .b "ABSTRACT" .eh 'SMM:06-%''The 4.4BSD NFS Implementation' .oh 'The 4.4BSD NFS Implementation''SMM:06-%' .pp The 4.4BSD implementation of the Network File System (NFS)\** is intended to interoperate with .(f \**Network File System (NFS) is believed to be a registered trademark of Sun Microsystems Inc. .)f other NFS Version 2 Protocol (RFC1094) implementations but also allows use of an alternate protocol that is hoped to provide better performance in certain environments. This paper will informally discuss these various protocol features and their use. There is a brief overview of the implementation followed by several sections on various problem areas related to NFS and some hints on how to deal with them. .pp Not Quite NFS (NQNFS) is an NFS like protocol designed to maintain full cache consistency between clients in a crash tolerant manner. It is an adaptation of the NFS protocol such that the server supports both NFS and NQNFS clients while maintaining full consistency between the server and NQNFS clients. It borrows heavily from work done on Spritely-NFS [Srinivasan89], but uses Leases [Gray89] to avoid the need to recover server state information after a crash. .sp