1.\" $NetBSD: fsck_ext2fs.8,v 1.19 2010/02/21 13:26:45 wiz Exp $ 2.\" 3.\" Copyright (c) 1980, 1989, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" Copyright (c) 1997 Manuel Bouyer. 31.\" 32.\" Redistribution and use in source and binary forms, with or without 33.\" modification, are permitted provided that the following conditions 34.\" are met: 35.\" 1. Redistributions of source code must retain the above copyright 36.\" notice, this list of conditions and the following disclaimer. 37.\" 2. Redistributions in binary form must reproduce the above copyright 38.\" notice, this list of conditions and the following disclaimer in the 39.\" documentation and/or other materials provided with the distribution. 40.\" 41.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 42.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 43.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 44.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 45.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 47.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 48.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 49.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 50.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 51.\" 52.\" @(#)fsck.8 8.3 (Berkeley) 11/29/94 53.\" 54.Dd October 9, 2008 55.Dt FSCK_EXT2FS 8 56.Os 57.Sh NAME 58.Nm fsck_ext2fs 59.Nd ext2 File System consistency check and interactive repair 60.Sh SYNOPSIS 61.Nm 62.Op Fl dfnpUy 63.Op Fl b Ar block# 64.Op Fl c Ar level 65.Op Fl m Ar mode 66.Ar filesystem ... 67.Sh DESCRIPTION 68.Nm 69performs interactive filesystem consistency checks and repair for each of 70the filesystems specified on the command line. 71It is normally invoked from 72.Xr fsck 8 . 73.Pp 74The kernel takes care that only a restricted class of innocuous filesystem 75inconsistencies can happen unless hardware or software failures intervene. 76These are limited to the following: 77.Pp 78.Bl -item -compact 79.It 80Unreferenced inodes 81.It 82Link counts in inodes too large 83.It 84Missing blocks in the free map 85.It 86Blocks in the free map also in files 87.It 88Counts in the super-block wrong 89.El 90.Pp 91These are the only inconsistencies that 92.Nm 93in 94.Dq preen 95mode (with the 96.Fl p 97option) will correct; if it encounters other inconsistencies, it exits 98with an abnormal return status. 99For each corrected inconsistency one or more lines will be printed 100identifying the filesystem on which the correction will take place, 101and the nature of the correction. 102After successfully correcting a filesystem, 103.Nm 104will print the number of files on that filesystem 105and the number of used and free blocks. 106.Pp 107If sent a 108.Dv QUIT 109signal, 110.Nm 111will finish the filesystem checks, then exit with an abnormal return status. 112.Pp 113Without the 114.Fl p 115option, 116.Nm 117audits and interactively repairs inconsistent conditions for filesystems. 118If the filesystem is inconsistent the operator is prompted for concurrence 119before each correction is attempted. 120It should be noted that some of the corrective actions which are not 121correctable under the 122.Fl p 123option will result in some loss of data. 124The amount and severity of data lost may be determined from the diagnostic 125output. 126The default action for each consistency correction 127is to wait for the operator to respond 128.Li yes 129or 130.Li no . 131If the operator does not have write permission on the filesystem 132.Nm 133will default to a 134.Fl n 135action. 136.Pp 137The following flags are interpreted by 138.Nm . 139.Bl -tag -width indent 140.It Fl b 141Use the block specified immediately after the flag as 142the super block for the filesystem. 143Block 8193 is usually an alternate super block. 144.It Fl d 145Print debugging output. 146.It Fl f 147Force checking of file systems. 148Normally, if a file system is cleanly unmounted, the kernel will set a 149.Dq clean flag 150in the file system superblock, and 151.Nm 152will not check the file system. 153This option forces 154.Nm 155to check the file system, regardless of the state of the clean flag. 156.It Fl m 157Use the mode specified in octal immediately after the flag as the 158permission bits to use when creating the 159.Pa lost+found 160directory rather than the default 1777. 161In particular, systems that do not wish to have lost files accessible 162by all users on the system should use a more restrictive 163set of permissions such as 700. 164.It Fl n 165Assume a no response to all questions asked by 166.Nm 167except for 168.Ql CONTINUE? , 169which is assumed to be affirmative; 170do not open the filesystem for writing. 171.It Fl p 172Specify 173.Dq preen 174mode, described above. 175.It Fl U 176Resolve numeric userids to usernames. 177.It Fl y 178Assume a yes response to all questions asked by 179.Nm ; 180this should be used with great caution as this is a free license 181to continue after essentially unlimited trouble has been encountered. 182.El 183.Pp 184Inconsistencies checked are as follows: 185.Bl -enum -offset indent -compact 186.It 187Blocks claimed by more than one inode or the free map. 188.It 189Blocks claimed by an inode outside the range of the filesystem. 190.It 191Incorrect link counts. 192.It 193Size checks: 194.Bl -item -offset indent -compact 195.It 196Directory size not a multiple of filesystem block size. 197.It 198Partially truncated file. 199.El 200.It 201Bad inode format. 202.It 203Blocks not accounted for anywhere. 204.It 205Directory checks: 206.Bl -item -offset indent -compact 207.It 208File pointing to unallocated inode. 209.It 210Inode number out of range. 211.It 212Dot or dot-dot not the first two entries of a directory 213or having the wrong inode number. 214.El 215.It 216Super Block checks: 217.Bl -item -offset indent -compact 218.It 219More blocks for inodes than there are in the filesystem. 220.It 221Bad free block map format. 222.It 223Total free block and/or free inode count incorrect. 224.El 225.El 226.Pp 227Orphaned files and directories (allocated but unreferenced) are, 228with the operator's concurrence, reconnected by 229placing them in the 230.Pa lost+found 231directory. 232The name assigned is the inode number. 233If the 234.Pa lost+found 235directory does not exist, it is created. 236If there is insufficient space its size is increased. 237.Pp 238Because of inconsistencies between the block device and the buffer cache, 239the raw device should always be used. 240.Sh DIAGNOSTICS 241The diagnostics produced by 242.Nm 243are fully enumerated and explained in Appendix A of 244.Rs 245.%T "Fsck \- The UNIX File System Check Program" 246.Re 247.Sh SEE ALSO 248.Xr fs 5 , 249.Xr fstab 5 , 250.Xr fsck 8 , 251.Xr fsdb 8 , 252.Xr newfs 8 , 253.Xr reboot 8 254