1 .\" $NetBSD: 0.t,v 1.2 1998/01/09 06:55:29 perry Exp $
3 .\" Copyright (c) 1986, 1993
4 .\" The Regents of the University of California. All rights reserved.
6 .\" Redistribution and use in source and binary forms, with or without
7 .\" modification, are permitted provided that the following conditions
9 .\" 1. Redistributions of source code must retain the above copyright
10 .\" notice, this list of conditions and the following disclaimer.
11 .\" 2. Redistributions in binary form must reproduce the above copyright
12 .\" notice, this list of conditions and the following disclaimer in the
13 .\" documentation and/or other materials provided with the distribution.
14 .\" 3. Neither the name of the University nor the names of its contributors
15 .\" may be used to endorse or promote products derived from this software
16 .\" without specific prior written permission.
18 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 .\" @(#)0.t 8.1 (Berkeley) 6/8/93
37 A Fast File System for UNIX*
38 .EH 'SMM:05-%''A Fast File System for \s-2UNIX\s+2'
39 .OH 'A Fast File System for \s-2UNIX\s+2''SMM:05-%'
41 Marshall Kirk McKusick, William N. Joy\(dg,
42 Samuel J. Leffler\(dd, Robert S. Fabry
44 Computer Systems Research Group
45 Computer Science Division
46 Department of Electrical Engineering and Computer Science
47 University of California, Berkeley
51 * UNIX is a trademark of Bell Laboratories.
54 \(dg William N. Joy is currently employed by:
55 Sun Microsystems, Inc, 2550 Garcia Avenue, Mountain View, CA 94043
58 \(dd Samuel J. Leffler is currently employed by:
59 Lucasfilm Ltd., PO Box 2009, San Rafael, CA 94912
62 This work was done under grants from
63 the National Science Foundation under grant MCS80-05144,
64 and the Defense Advance Research Projects Agency (DoD) under
65 ARPA Order No. 4031 monitored by Naval Electronic System Command under
66 Contract No. N00039-82-C-0235.
68 A reimplementation of the UNIX file system is described.
69 The reimplementation provides substantially higher throughput
70 rates by using more flexible allocation policies
71 that allow better locality of reference and can
72 be adapted to a wide range of peripheral and processor characteristics.
73 The new file system clusters data that is sequentially accessed
74 and provides two block sizes to allow fast access to large files
75 while not wasting large amounts of space for small files.
76 File access rates of up to ten times faster than the traditional
77 UNIX file system are experienced.
78 Long needed enhancements to the programmers'
79 interface are discussed.
80 These include a mechanism to place advisory locks on files,
81 extensions of the name space across file systems,
82 the ability to use long file names,
83 and provisions for administrative control of resource usage.
86 Revised February 18, 1984
90 CR Categories and Subject Descriptors:
92 .B "[Operating Systems]":
93 File Systems Management \-
94 .I "file organization, directory structures, access methods";
96 .B "[Operating Systems]":
98 .I "allocation/deallocation strategies, secondary storage devices";
100 .B "[Operating Systems]":
102 .I "measurements, operational analysis";
104 .B "[Information Systems]":
105 Information Storage \-
106 .I "file organization"
108 Additional Keywords and Phrases:
110 file system organization,
111 file system performance,
113 application program interface.
121 .B "TABLE OF CONTENTS"
129 .B "2. Old file system
133 .B "3. New file system organization
134 3.1. Optimizing storage utilization
135 3.2. File system parameterization
144 .B "5. File system functional enhancements