1994-05-26 06:35:07 +00:00
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.\" Copyright (c) 1986, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the University of
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.\" California, Berkeley and its contributors.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)0.t 8.1 (Berkeley) 6/8/93
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.\"
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.if n .ND
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.TL
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Fsck \- The UNIX\(dg File System Check Program
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.EH 'SMM:3-%''The \s-2UNIX\s+2 File System Check Program'
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.OH 'The \s-2UNIX\s+2 File System Check Program''SMM:3-%'
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.AU
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Marshall Kirk McKusick
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.AI
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Computer Systems Research Group
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Computer Science Division
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Department of Electrical Engineering and Computer Science
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University of California, Berkeley
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Berkeley, CA 94720
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.AU
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T. J. Kowalski
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.AI
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Bell Laboratories
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Murray Hill, New Jersey 07974
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.AB
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.FS
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\(dgUNIX is a trademark of Bell Laboratories.
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.FE
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.FS
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This work was done under grants from
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the National Science Foundation under grant MCS80-05144,
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and the Defense Advance Research Projects Agency (DoD) under
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Arpa Order No. 4031 monitored by Naval Electronic System Command under
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Contract No. N00039-82-C-0235.
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.FE
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This document reflects the use of
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.I fsck
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with the 4.2BSD and 4.3BSD file system organization. This
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is a revision of the
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original paper written by
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T. J. Kowalski.
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.PP
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File System Check Program (\fIfsck\fR)
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is an interactive file system check and repair program.
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.I Fsck
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uses the redundant structural information in the
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UNIX file system to perform several consistency checks.
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If an inconsistency is detected, it is reported
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to the operator, who may elect to fix or ignore
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each inconsistency.
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These inconsistencies result from the permanent interruption
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of the file system updates, which are performed every
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time a file is modified.
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Unless there has been a hardware failure,
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.I fsck
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is able to repair corrupted file systems
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using procedures based upon the order in which UNIX honors
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these file system update requests.
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.PP
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The purpose of this document is to describe the normal updating
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of the file system,
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to discuss the possible causes of file system corruption,
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and to present the corrective actions implemented
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by
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.I fsck.
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Both the program and the interaction between the
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program and the operator are described.
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.sp 2
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.LP
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1996-10-08 14:54:53 +00:00
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Revised October 7, 1996
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1994-05-26 06:35:07 +00:00
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.AE
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.LP
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.bp
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.ce
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.B "TABLE OF CONTENTS"
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.LP
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.sp 1
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.nf
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.B "1. Introduction"
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.LP
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.sp .5v
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.nf
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.B "2. Overview of the file system
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2.1. Superblock
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2.2. Summary Information
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2.3. Cylinder groups
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2.4. Fragments
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2.5. Updates to the file system
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.LP
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.sp .5v
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.nf
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.B "3. Fixing corrupted file systems
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3.1. Detecting and correcting corruption
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3.2. Super block checking
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3.3. Free block checking
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3.4. Checking the inode state
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3.5. Inode links
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3.6. Inode data size
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3.7. Checking the data associated with an inode
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3.8. File system connectivity
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.LP
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.sp .5v
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.nf
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.B Acknowledgements
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.LP
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.sp .5v
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.nf
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.B References
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.LP
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.sp .5v
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.nf
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.B "4. Appendix A
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4.1. Conventions
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4.2. Initialization
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4.3. Phase 1 - Check Blocks and Sizes
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4.4. Phase 1b - Rescan for more Dups
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4.5. Phase 2 - Check Pathnames
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4.6. Phase 3 - Check Connectivity
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4.7. Phase 4 - Check Reference Counts
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4.8. Phase 5 - Check Cyl groups
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4.9. Cleanup
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.ds RH Introduction
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.bp
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