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.\" Copyright (c) 1986, 1993
.\" 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. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgement:
.\" This product includes software developed by the University of
.\" California, Berkeley and its contributors.
.\" 4. 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.
.\"
.\" $FreeBSD$
.\" @(#)0.t 8.1 (Berkeley) 6/8/93
.\"
.if n .ND
.TL
Fsck_ffs \- The UNIX\(dg File System Check Program
.EH 'SMM:3-%''The \s-2UNIX\s+2 File System Check Program'
.OH 'The \s-2UNIX\s+2 File System Check Program''SMM:3-%'
.AU
Marshall Kirk McKusick
.AI
Computer Systems Research Group
Computer Science Division
Department of Electrical Engineering and Computer Science
University of California, Berkeley
Berkeley, CA 94720
.AU
T. J. Kowalski
.AI
Bell Laboratories
Murray Hill, New Jersey 07974
.AB
.FS
\(dgUNIX is a trademark of Bell Laboratories.
.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
This document reflects the use of
.I fsck_ffs
with the 4.2BSD and 4.3BSD filesystem organization. This
is a revision of the
original paper written by
T. J. Kowalski.
.PP
File System Check Program (\fIfsck_ffs\fR)
is an interactive filesystem check and repair program.
.I Fsck_ffs
uses the redundant structural information in the
UNIX filesystem to perform several consistency checks.
If an inconsistency is detected, it is reported
to the operator, who may elect to fix or ignore
each inconsistency.
These inconsistencies result from the permanent interruption
of the filesystem updates, which are performed every
time a file is modified.
Unless there has been a hardware failure,
.I fsck_ffs
is able to repair corrupted filesystems
using procedures based upon the order in which UNIX honors
these filesystem update requests.
.PP
The purpose of this document is to describe the normal updating
of the filesystem,
to discuss the possible causes of filesystem corruption,
and to present the corrective actions implemented
by
.I fsck_ffs.
Both the program and the interaction between the
program and the operator are described.
.sp 2
.LP
Revised October 7, 1996
.AE
.LP
.bp
.ce
.B "TABLE OF CONTENTS"
.LP
.sp 1
.nf
.B "1. Introduction"
.LP
.sp .5v
.nf
.B "2. Overview of the filesystem
2.1. Superblock
2.2. Summary Information
2.3. Cylinder groups
2.4. Fragments
2.5. Updates to the filesystem
.LP
.sp .5v
.nf
.B "3. Fixing corrupted filesystems
3.1. Detecting and correcting corruption
3.2. Super block checking
3.3. Free block checking
3.4. Checking the inode state
3.5. Inode links
3.6. Inode data size
3.7. Checking the data associated with an inode
3.8. File system connectivity
.LP
.sp .5v
.nf
.B Acknowledgements
.LP
.sp .5v
.nf
.B References
.LP
.sp .5v
.nf
.B "4. Appendix A
4.1. Conventions
4.2. Initialization
4.3. Phase 1 - Check Blocks and Sizes
4.4. Phase 1b - Rescan for more Dups
4.5. Phase 2 - Check Pathnames
4.6. Phase 3 - Check Connectivity
4.7. Phase 4 - Check Reference Counts
4.8. Phase 5 - Check Cyl groups
4.9. Cleanup
.ds RH Introduction
.bp
|
