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: src/sbin/fsck/fsck.8,v 1.14.2.3 2001/01/23 23:11:07 iedowse Exp $ 35.\" 36.Dd April 20, 2007 37.Dt FSCK 8 38.Os 39.Sh NAME 40.Nm fsck 41.Nd UFS filesystem consistency check and interactive repair 42.Sh SYNOPSIS 43.Nm 44.Fl p 45.Op Fl f 46.Op Fl m Ar mode 47.Op Ar filesystem 48.Ar ... 49.Nm 50.Op Fl Lny 51.Op Fl b Ar block# 52.Op Fl c Ar level 53.Op Fl l Ar maxparallel 54.Op Fl m Ar mode 55.Op Ar filesystem 56.Ar ... 57.Sh DESCRIPTION 58The first form of 59.Nm 60preens a standard set of filesystems or the specified filesystems. 61It is normally used in the script 62.Pa /etc/rc 63during automatic reboot. 64Here 65.Nm 66reads the table 67.Pa /etc/fstab 68to determine which filesystems to check. 69Only partitions in fstab that are mounted ``rw,'' ``rq'' or ``ro'' 70and that have non-zero pass number are checked. 71Filesystems with pass number 1 (normally just the root filesystem) 72are checked one at a time. 73When pass 1 completes, all remaining filesystems are checked, 74running one process per disk drive. 75The disk drive containing each filesystem is inferred from the longest prefix 76of the device name that ends in a digit; the remaining characters are assumed 77to be the partition designator. 78.Pp 79In "preen" mode the clean flag of each filesystem's superblock is examined 80and only those filesystems that 81are not marked clean are checked. 82Filesystems are marked clean when they are unmounted, 83when they have been mounted read-only, or when 84.Nm 85runs on them successfully. 86If the 87.Fl f 88option is specified, the filesystems 89will be checked regardless of the state of their clean flag. 90.Pp 91The kernel takes care that only a restricted class of innocuous filesystem 92inconsistencies can happen unless hardware or software failures intervene. 93These are limited to the following: 94.Pp 95.Bl -item -compact -offset indent 96.It 97Unreferenced inodes 98.It 99Link counts in inodes too large 100.It 101Missing blocks in the free map 102.It 103Blocks in the free map also in files 104.It 105Counts in the super-block wrong 106.El 107.Pp 108These are the only inconsistencies that 109.Nm 110with the 111.Fl p 112option will correct; if it encounters other inconsistencies, it exits 113with an abnormal return status and an automatic reboot will then fail. 114For each corrected inconsistency one or more lines will be printed 115identifying the filesystem on which the correction will take place, 116and the nature of the correction. After successfully correcting a filesystem, 117.Nm 118will print the number of files on that filesystem, 119the number of used and free blocks, 120and the percentage of fragmentation. 121.Pp 122If sent a 123.Dv QUIT 124signal, 125.Nm 126will finish the filesystem checks, then exit with an abnormal 127return status that causes an automatic reboot to fail. 128This is useful when you want to finish the filesystem checks during an 129automatic reboot, 130but do not want the machine to come up multiuser after the checks complete. 131.Pp 132If 133.Nm 134receives a 135.Dv SIGINFO 136(see the 137.Dq status 138argument for 139.Xr stty 1 ) 140signal, a line will be written to the standard output indicating 141the name of the device currently being checked, the current phase 142number and phase-specific progress information. 143.Pp 144Without the 145.Fl p 146option, 147.Nm 148audits and interactively repairs inconsistent conditions for filesystems. 149If the filesystem is inconsistent the operator is prompted for concurrence 150before each correction is attempted. 151It should be noted that some of the corrective actions which are not 152correctable under the 153.Fl p 154option will result in some loss of data. 155The amount and severity of data lost may be determined from the diagnostic 156output. 157The default action for each consistency correction 158is to wait for the operator to respond 159.Li yes 160or 161.Li no . 162If the operator does not have write permission on the filesystem 163.Nm 164will default to a 165.Fl n 166action. 167.Pp 168.Nm Fsck 169has more consistency checks than 170its predecessors 171.Em check , dcheck , fcheck , 172and 173.Em icheck 174combined. 175.Pp 176The following flags are interpreted by 177.Nm . 178.Bl -tag -width indent 179.It Fl b 180Use the block specified immediately after the flag as 181the super block for the filesystem. Block 32 is usually 182an alternate super block. 183.It Fl c 184Convert the filesystem to the specified level. 185Note that the level of a filesystem can only be raised. 186.Pp 187There are currently four levels defined: 188.Bl -tag -width indent 189.It 0 190The filesystem is in the old (static table) format. 191.It 1 192The filesystem is in the new (dynamic table) format. 193.It 2 194The filesystem supports 32-bit uid's and gid's, 195short symbolic links are stored in the inode, 196and directories have an added field showing the file type. 197.It 3 198If maxcontig is greater than one, 199build the free segment maps to aid in finding contiguous sets of blocks. 200If maxcontig is equal to one, delete any existing segment maps. 201.El 202.Pp 203In interactive mode, 204.Nm 205will list the conversion to be made 206and ask whether the conversion should be done. 207If a negative answer is given, 208no further operations are done on the filesystem. 209In preen mode, 210the conversion is listed and done if 211possible without user interaction. 212Conversion in preen mode is best used when all the filesystems 213are being converted at once. 214The format of a filesystem can be determined from the 215first line of output from 216.Xr dumpfs 8 . 217.It Fl f 218Force 219.Nm 220to check 221.Sq clean 222filesystems when preening. 223.It Fl l 224Limit the number of parallel checks to the number specified in the following 225argument. 226By default, the limit is the number of disks, running one process per disk. 227If a smaller limit is given, the disks are checked round-robin, one filesystem 228at a time. 229.It Fl L 230Just print the "last mounted on" information and exit, do no other checking. 231.It Fl m 232Use the mode specified in octal immediately after the flag as the 233permission bits to use when creating the 234.Pa lost+found 235directory rather than the default 1777. 236In particular, systems that do not wish to have lost files accessible 237by all users on the system should use a more restrictive 238set of permissions such as 700. 239.It Fl n 240Assume a no response to all questions asked by 241.Nm 242except for 243.Ql CONTINUE? , 244which is assumed to be affirmative; 245do not open the filesystem for writing. 246.It Fl p 247Preen filesystems (see above). 248.It Fl y 249Assume a yes response to all questions asked by 250.Nm ; 251this should be used with great caution as this is a free license 252to continue after essentially unlimited trouble has been encountered. 253.El 254.Pp 255If no filesystems are given to 256.Nm 257then a default list of filesystems is read from 258the file 259.Pa /etc/fstab . 260.Pp 261Inconsistencies checked are as follows: 262.Bl -enum -compact 263.It 264Blocks claimed by more than one inode or the free map. 265.It 266Blocks claimed by an inode outside the range of the filesystem. 267.It 268Incorrect link counts. 269.It 270Size checks: 271.Bl -item -offset indent -compact 272.It 273Directory size not a multiple of DIRBLKSIZ. 274.It 275Partially truncated file. 276.El 277.It 278Bad inode format. 279.It 280Blocks not accounted for anywhere. 281.It 282Directory checks: 283.Bl -item -offset indent -compact 284.It 285File pointing to unallocated inode. 286.It 287Inode number out of range. 288.It 289Directories with unallocated blocks (holes). 290.It 291Dot or dot-dot not the first two entries of a directory 292or having the wrong inode number. 293.El 294.It 295Super Block checks: 296.Bl -item -offset indent -compact 297.It 298More blocks for inodes than there are in the filesystem. 299.It 300Bad free block map format. 301.It 302Total free block and/or free inode count incorrect. 303.El 304.El 305.Pp 306Orphaned files and directories (allocated but unreferenced) are, 307with the operator's concurrence, reconnected by 308placing them in the 309.Pa lost+found 310directory. 311The name assigned is the inode number. 312If the 313.Pa lost+found 314directory does not exist, it is created. 315If there is insufficient space its size is increased. 316.Pp 317Because of inconsistencies between the block device and the buffer cache, 318the raw device should always be used. 319.Sh FILES 320.Bl -tag -width /etc/fstab -compact 321.It Pa /etc/fstab 322contains default list of filesystems to check. 323.El 324.Sh DIAGNOSTICS 325The diagnostics produced by 326.Nm 327are fully enumerated and explained in Appendix A of 328.Rs 329.%T "Fsck \- The UNIX File System Check Program" 330.Re 331.Sh SEE ALSO 332.Xr fs 5 , 333.Xr fstab 5 , 334.Xr UFS 5 , 335.Xr fsdb 8 , 336.Xr newfs 8 , 337.Xr reboot 8 338