1.\" $NetBSD: fsck_ext2fs.8,v 1.17 2009/03/15 10:01:47 joerg 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.\" 3. All advertising materials mentioning features or use of this software 41.\" must display the following acknowledgement: 42.\" This product includes software developed by Manuel Bouyer. 43.\" 4. The name of the author may not be used to endorse or promote products 44.\" derived from this software without specific prior written permission. 45.\" 46.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 47.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 48.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 49.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 50.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 51.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 52.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 53.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 54.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 55.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 56.\" 57.\" @(#)fsck.8 8.3 (Berkeley) 11/29/94 58.\" 59.Dd October 9, 2008 60.Dt FSCK_EXT2FS 8 61.Os 62.Sh NAME 63.Nm fsck_ext2fs 64.Nd EXT2 File System consistency check and interactive repair 65.Sh SYNOPSIS 66.Nm 67.Op Fl dfnpUy 68.Op Fl b Ar block# 69.Op Fl c Ar level 70.Op Fl m Ar mode 71.Ar filesystem ... 72.Sh DESCRIPTION 73.Nm 74performs interactive filesystem consistency checks and repair for each of 75the filesystems specified on the command line. 76It is normally invoked from 77.Xr fsck 8 . 78.Pp 79The kernel takes care that only a restricted class of innocuous filesystem 80inconsistencies can happen unless hardware or software failures intervene. 81These are limited to the following: 82.Pp 83.Bl -item -compact 84.It 85Unreferenced inodes 86.It 87Link counts in inodes too large 88.It 89Missing blocks in the free map 90.It 91Blocks in the free map also in files 92.It 93Counts in the super-block wrong 94.El 95.Pp 96These are the only inconsistencies that 97.Nm 98in 99.Dq preen 100mode (with the 101.Fl p 102option) will correct; if it encounters other inconsistencies, it exits 103with an abnormal return status. 104For each corrected inconsistency one or more lines will be printed 105identifying the filesystem on which the correction will take place, 106and the nature of the correction. 107After successfully correcting a filesystem, 108.Nm 109will print the number of files on that filesystem 110and the number of used and free blocks. 111.Pp 112If sent a 113.Dv QUIT 114signal, 115.Nm 116will finish the filesystem checks, then exit with an abnormal return status. 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 b 146Use the block specified immediately after the flag as 147the super block for the filesystem. 148Block 8193 is usually an alternate super block. 149.It Fl d 150Print debugging output. 151.It Fl f 152Force checking of file systems. 153Normally, if a file system is cleanly unmounted, the kernel will set a 154.Dq clean flag 155in the file system superblock, and 156.Nm 157will not check the file system. 158This option forces 159.Nm 160to check the file system, regardless of the state of the clean flag. 161.It Fl m 162Use the mode specified in octal immediately after the flag as the 163permission bits to use when creating the 164.Pa lost+found 165directory rather than the default 1777. 166In particular, systems that do not wish to have lost files accessible 167by all users on the system should use a more restrictive 168set of permissions such as 700. 169.It Fl n 170Assume a no response to all questions asked by 171.Nm 172except for 173.Ql CONTINUE? , 174which is assumed to be affirmative; 175do not open the filesystem for writing. 176.It Fl p 177Specify 178.Dq preen 179mode, described above. 180.It Fl U 181Resolve numeric userids to usernames. 182.It Fl y 183Assume a yes response to all questions asked by 184.Nm ; 185this should be used with great caution as this is a free license 186to continue after essentially unlimited trouble has been encountered. 187.El 188.Pp 189Inconsistencies checked are as follows: 190.Bl -enum -offset indent -compact 191.It 192Blocks claimed by more than one inode or the free map. 193.It 194Blocks claimed by an inode outside the range of the filesystem. 195.It 196Incorrect link counts. 197.It 198Size checks: 199.Bl -item -offset indent -compact 200.It 201Directory size not a multiple of filesystem block size. 202.It 203Partially truncated file. 204.El 205.It 206Bad inode format. 207.It 208Blocks not accounted for anywhere. 209.It 210Directory checks: 211.Bl -item -offset indent -compact 212.It 213File pointing to unallocated inode. 214.It 215Inode number out of range. 216.It 217Dot or dot-dot not the first two entries of a directory 218or having the wrong inode number. 219.El 220.It 221Super Block checks: 222.Bl -item -offset indent -compact 223.It 224More blocks for inodes than there are in the filesystem. 225.It 226Bad free block map format. 227.It 228Total free block and/or free inode count incorrect. 229.El 230.El 231.Pp 232Orphaned files and directories (allocated but unreferenced) are, 233with the operator's concurrence, reconnected by 234placing them in the 235.Pa lost+found 236directory. 237The name assigned is the inode number. 238If the 239.Pa lost+found 240directory does not exist, it is created. 241If there is insufficient space its size is increased. 242.Pp 243Because of inconsistencies between the block device and the buffer cache, 244the raw device should always be used. 245.Sh DIAGNOSTICS 246The diagnostics produced by 247.Nm 248are fully enumerated and explained in Appendix A of 249.Rs 250.%T "Fsck \- The UNIX File System Check Program" 251.Re 252.Sh SEE ALSO 253.Xr fs 5 , 254.Xr fstab 5 , 255.Xr fsck 8 , 256.Xr fsdb 8 , 257.Xr newfs 8 , 258.Xr reboot 8 259