Copyright (c) 1986, 1993
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delim $$ .EN A Fast File System for UNIX* .EH 'SMM:05-%''A Fast File System for \s-2UNIX\s+2' .OH 'A Fast File System for \s-2UNIX\s+2''SMM:05-%' .AU Marshall Kirk McKusick, William N. Joy\(dg, Samuel J. Leffler\(dd, Robert S. Fabry .AI Computer Systems Research Group Computer Science Division Department of Electrical Engineering and Computer Science University of California, Berkeley Berkeley, CA 94720 .AB .FS * UNIX is a trademark of Bell Laboratories. .FE .FS \(dg William N. Joy is currently employed by: Sun Microsystems, Inc, 2550 Garcia Avenue, Mountain View, CA 94043 .FE .FS \(dd Samuel J. Leffler is currently employed by: Lucasfilm Ltd., PO Box 2009, San Rafael, CA 94912 .FE .FS This work was done under grants from the National Science Foundation under grant MCS80-05144, and the Defense Advance Research Projects Agency (DoD) under ARPA Order No. 4031 monitored by Naval Electronic System Command under Contract No. N00039-82-C-0235. .FE A reimplementation of the UNIX file system is described. The reimplementation provides substantially higher throughput rates by using more flexible allocation policies that allow better locality of reference and can be adapted to a wide range of peripheral and processor characteristics. The new file system clusters data that is sequentially accessed and provides two block sizes to allow fast access to large files while not wasting large amounts of space for small files. File access rates of up to ten times faster than the traditional UNIX file system are experienced. Long needed enhancements to the programmers' interface are discussed. These include a mechanism to place advisory locks on files, extensions of the name space across file systems, the ability to use long file names, and provisions for administrative control of resource usage.
The Regents of the University of California. All rights reserved.
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.
delim $$ .EN A Fast File System for UNIX* .EH 'SMM:05-%''A Fast File System for \s-2UNIX\s+2' .OH 'A Fast File System for \s-2UNIX\s+2''SMM:05-%' .AU Marshall Kirk McKusick, William N. Joy\(dg, Samuel J. Leffler\(dd, Robert S. Fabry .AI Computer Systems Research Group Computer Science Division Department of Electrical Engineering and Computer Science University of California, Berkeley Berkeley, CA 94720 .AB .FS * UNIX is a trademark of Bell Laboratories. .FE .FS \(dg William N. Joy is currently employed by: Sun Microsystems, Inc, 2550 Garcia Avenue, Mountain View, CA 94043 .FE .FS \(dd Samuel J. Leffler is currently employed by: Lucasfilm Ltd., PO Box 2009, San Rafael, CA 94912 .FE .FS This work was done under grants from the National Science Foundation under grant MCS80-05144, and the Defense Advance Research Projects Agency (DoD) under ARPA Order No. 4031 monitored by Naval Electronic System Command under Contract No. N00039-82-C-0235. .FE A reimplementation of the UNIX file system is described. The reimplementation provides substantially higher throughput rates by using more flexible allocation policies that allow better locality of reference and can be adapted to a wide range of peripheral and processor characteristics. The new file system clusters data that is sequentially accessed and provides two block sizes to allow fast access to large files while not wasting large amounts of space for small files. File access rates of up to ten times faster than the traditional UNIX file system are experienced. Long needed enhancements to the programmers' interface are discussed. These include a mechanism to place advisory locks on files, extensions of the name space across file systems, the ability to use long file names, and provisions for administrative control of resource usage.
Revised February 18, 1984 .AE
CR Categories and Subject Descriptors: D.4.3 "[Operating Systems]": File Systems Management - "file organization, directory structures, access methods"; D.4.2 "[Operating Systems]": Storage Management - "allocation/deallocation strategies, secondary storage devices"; D.4.8 "[Operating Systems]": Performance - "measurements, operational analysis"; H.3.2 "[Information Systems]": Information Storage - "file organization" Additional Keywords and Phrases: UNIX, file system organization, file system performance, file system design, application program interface. General Terms: file system, measurement, performance. .bp
"TABLE OF CONTENTS"
"1. Introduction"
"2. Old file system
"3. New file system organization 3.1. Optimizing storage utilization 3.2. File system parameterization 3.3. Layout policies
"4. Performance
"5. File system functional enhancements 5.1. Long file names 5.2. File locking 5.3. Symbolic links 5.4. Rename 5.5. Quotas
Acknowledgements
References