1.\" 2.\" Copyright (c) 1980, 1989, 1991, 1993 3.\" The Regents of the University of California. All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. All advertising materials mentioning features or use of this software 14.\" must display the following acknowledgment: 15.\" This product includes software developed by the University of 16.\" California, Berkeley and its contributors. 17.\" 4. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" @(#)fsck.8 8.4 (Berkeley) 5/9/95 34.\" $FreeBSD$ 35.\" 36.Dd April 24, 2001 37.Dt FSCK_FFS 8 38.Os 39.Sh NAME 40.Nm fsck_ffs , 41.Nm fsck_ufs 42.Nd filesystem consistency check and interactive repair 43.Sh SYNOPSIS 44.Nm 45.Op Fl BFpfny 46.Op Fl b Ar block# 47.Op Fl c Ar level 48.Op Fl m Ar mode 49.Ar filesystem 50.Ar ... 51.Sh DESCRIPTION 52The specified disk partitions and/or filesystems are checked. 53In "preen" mode the clean flag of each filesystem's superblock is examined 54and only those filesystems that 55are not marked clean are checked. 56Filesystems are marked clean when they are unmounted, 57when they have been mounted read-only, or when 58.Nm 59runs on them successfully. 60If the 61.Fl f 62option is specified, the filesystems 63will be checked regardless of the state of their clean flag. 64.Pp 65The kernel takes care that only a restricted class of innocuous filesystem 66inconsistencies can happen unless hardware or software failures intervene. 67These are limited to the following: 68.Pp 69.Bl -item -compact -offset indent 70.It 71Unreferenced inodes 72.It 73Link counts in inodes too large 74.It 75Missing blocks in the free map 76.It 77Blocks in the free map also in files 78.It 79Counts in the super-block wrong 80.El 81.Pp 82These are the only inconsistencies that 83.Nm 84with the 85.Fl p 86option will correct; if it encounters other inconsistencies, it exits 87with an abnormal return status and an automatic reboot will then fail. 88For each corrected inconsistency one or more lines will be printed 89identifying the filesystem on which the correction will take place, 90and the nature of the correction. After successfully correcting a filesystem, 91.Nm 92will print the number of files on that filesystem, 93the number of used and free blocks, 94and the percentage of fragmentation. 95.Pp 96If sent a 97.Dv QUIT 98signal, 99.Nm 100will finish the filesystem checks, then exit with an abnormal 101return status that causes an automatic reboot to fail. 102This is useful when you want to finish the filesystem checks during an 103automatic reboot, 104but do not want the machine to come up multiuser after the checks complete. 105.Pp 106If 107.Nm 108receives a 109.Dv SIGINFO 110(see the 111.Dq status 112argument for 113.Xr stty 1 ) 114signal, a line will be written to the standard output indicating 115the name of the device currently being checked, the current phase 116number and phase-specific progress information. 117.Pp 118Without the 119.Fl p 120option, 121.Nm 122audits and interactively repairs inconsistent conditions for filesystems. 123If the filesystem is inconsistent the operator is prompted for concurrence 124before each correction is attempted. 125It should be noted that some of the corrective actions which are not 126correctable under the 127.Fl p 128option will result in some loss of data. 129The amount and severity of data lost may be determined from the diagnostic 130output. 131The default action for each consistency correction 132is to wait for the operator to respond 133.Li yes 134or 135.Li no . 136If the operator does not have write permission on the filesystem 137.Nm 138will default to a 139.Fl n 140action. 141.Pp 142The following flags are interpreted by 143.Nm : 144.Bl -tag -width indent 145.It Fl F 146Determine whether the filesystem needs to be cleaned immediately 147in foreground, or if its cleaning can be deferred to background. 148To be eligible for background cleaning it must have been running 149with soft updates, not have been marked as needing a foreground check, 150and be mounted and writable when the background check is to be done. 151If these conditions are met, then 152.Nm 153exits with a zero exit status. 154Otherwise it exits with a non-zero exit status. 155If the filesystem is clean, 156it will exit with a non-zero exit status so that the clean status 157of the filesystem can be verified and reported during the foreground 158checks. 159Note that when invoked with the 160.Fl F 161flag, no cleanups are done. 162The only thing that 163.Nm 164does is to determine whether a foreground or background 165check is needed and exit with an appropriate status code. 166.It Fl B 167A check is done on the specified and possibly active filesystem. 168The set of corrections that can be done is limited to those done 169when running in preen mode (see the 170.Fl p 171flag). 172If unexpected errors are found, 173the filesystem is marked as needing a foreground check and 174.Nm 175exits without attempting any further cleaning. 176.It Fl b 177Use the block specified immediately after the flag as 178the super block for the filesystem. Block 32 is usually 179an alternate super block. 180.It Fl c 181Convert the filesystem to the specified level. 182Note that the level of a filesystem can only be raised. 183There are currently four levels defined: 184.Bl -tag -width indent 185.It 0 186The filesystem is in the old (static table) format. 187.It 1 188The filesystem is in the new (dynamic table) format. 189.It 2 190The filesystem supports 32-bit uid's and gid's, 191short symbolic links are stored in the inode, 192and directories have an added field showing the file type. 193.It 3 194If maxcontig is greater than one, 195build the free segment maps to aid in finding contiguous sets of blocks. 196If maxcontig is equal to one, delete any existing segment maps. 197.El 198.Pp 199In interactive mode, 200.Nm 201will list the conversion to be made 202and ask whether the conversion should be done. 203If a negative answer is given, 204no further operations are done on the filesystem. 205In preen mode, 206the conversion is listed and done if 207possible without user interaction. 208Conversion in preen mode is best used when all the filesystems 209are being converted at once. 210The format of a filesystem can be determined from the 211first line of output from 212.Xr dumpfs 8 . 213.It Fl f 214Force 215.Nm 216to check 217.Sq clean 218filesystems when preening. 219.It Fl m 220Use the mode specified in octal immediately after the flag as the 221permission bits to use when creating the 222.Pa lost+found 223directory rather than the default 1777. 224In particular, systems that do not wish to have lost files accessible 225by all users on the system should use a more restrictive 226set of permissions such as 700. 227.It Fl n 228Assume a no response to all questions asked by 229.Nm 230except for 231.Ql CONTINUE? , 232which is assumed to be affirmative; 233do not open the filesystem for writing. 234.It Fl p 235Preen filesystems (see above). 236.It Fl y 237Assume a yes response to all questions asked by 238.Nm ; 239this should be used with great caution as this is a free license 240to continue after essentially unlimited trouble has been encountered. 241.El 242.Pp 243Inconsistencies checked are as follows: 244.Pp 245.Bl -enum -compact 246.It 247Blocks claimed by more than one inode or the free map. 248.It 249Blocks claimed by an inode outside the range of the filesystem. 250.It 251Incorrect link counts. 252.It 253Size checks: 254.Bl -item -offset indent -compact 255.It 256Directory size not a multiple of DIRBLKSIZ. 257.It 258Partially truncated file. 259.El 260.It 261Bad inode format. 262.It 263Blocks not accounted for anywhere. 264.It 265Directory checks: 266.Bl -item -offset indent -compact 267.It 268File pointing to unallocated inode. 269.It 270Inode number out of range. 271.It 272Directories with unallocated blocks (holes). 273.It 274Dot or dot-dot not the first two entries of a directory 275or having the wrong inode number. 276.El 277.It 278Super Block checks: 279.Bl -item -offset indent -compact 280.It 281More blocks for inodes than there are in the filesystem. 282.It 283Bad free block map format. 284.It 285Total free block and/or free inode count incorrect. 286.El 287.El 288.Pp 289Orphaned files and directories (allocated but unreferenced) are, 290with the operator's concurrence, reconnected by 291placing them in the 292.Pa lost+found 293directory. 294The name assigned is the inode number. 295If the 296.Pa lost+found 297directory does not exist, it is created. 298If there is insufficient space its size is increased. 299.Sh FILES 300.Bl -tag -width /etc/fstab -compact 301.It Pa /etc/fstab 302contains default list of filesystems to check. 303.El 304.Sh DIAGNOSTICS 305.Ex -std 306.Pp 307The diagnostics produced by 308.Nm 309are fully enumerated and explained in Appendix A of 310.Rs 311.%T "Fsck \- The UNIX File System Check Program" 312.Re 313.Sh SEE ALSO 314.Xr fs 5 , 315.Xr fstab 5 , 316.Xr fsck 8 , 317.Xr fsdb 8 , 318.Xr newfs 8 , 319.Xr reboot 8 320