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.\" 4. Neither the name of the University nor the names of its contributors 14.\" may be used to endorse or promote products derived from this software 15.\" without specific prior written permission. 16.\" 17.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27.\" SUCH DAMAGE. 28.\" 29.\" @(#)fsck.8 8.4 (Berkeley) 5/9/95 30.\" $FreeBSD$ 31.\" 32.Dd January 25, 2009 33.Dt FSCK_FFS 8 34.Os 35.Sh NAME 36.Nm fsck_ffs , 37.Nm fsck_ufs 38.Nd file system consistency check and interactive repair 39.Sh SYNOPSIS 40.Nm 41.Op Fl BFprfny 42.Op Fl b Ar block 43.Op Fl c Ar level 44.Op Fl m Ar mode 45.Ar filesystem 46.Ar ... 47.Sh DESCRIPTION 48The specified disk partitions and/or file systems are checked. 49In "preen" or "check clean" mode the clean flag of each file system's 50superblock is examined and only those file systems that are not marked clean 51are checked. 52File systems are marked clean when they are unmounted, 53when they have been mounted read-only, or when 54.Nm 55runs on them successfully. 56If the 57.Fl f 58option is specified, the file systems 59will be checked regardless of the state of their clean flag. 60.Pp 61The kernel takes care that only a restricted class of innocuous file system 62inconsistencies can happen unless hardware or software failures intervene. 63These are limited to the following: 64.Pp 65.Bl -item -compact -offset indent 66.It 67Unreferenced inodes 68.It 69Link counts in inodes too large 70.It 71Missing blocks in the free map 72.It 73Blocks in the free map also in files 74.It 75Counts in the super-block wrong 76.El 77.Pp 78These are the only inconsistencies that 79.Nm 80with the 81.Fl p 82option will correct; if it encounters other inconsistencies, it exits 83with an abnormal return status and an automatic reboot will then fail. 84For each corrected inconsistency one or more lines will be printed 85identifying the file system on which the correction will take place, 86and the nature of the correction. 87After successfully correcting a file system, 88.Nm 89will print the number of files on that file system, 90the number of used and free blocks, 91and the percentage of fragmentation. 92.Pp 93If sent a 94.Dv QUIT 95signal, 96.Nm 97will finish the file system checks, then exit with an abnormal 98return status that causes an automatic reboot to fail. 99This is useful when you want to finish the file system checks during an 100automatic reboot, 101but do not want the machine to come up multiuser after the checks complete. 102.Pp 103If 104.Nm 105receives a 106.Dv SIGINFO 107(see the 108.Dq status 109argument for 110.Xr stty 1 ) 111signal, a line will be written to the standard output indicating 112the name of the device currently being checked, the current phase 113number and phase-specific progress information. 114.Pp 115Without the 116.Fl p 117option, 118.Nm 119audits and interactively repairs inconsistent conditions for file systems. 120If the file system is inconsistent the operator is prompted for concurrence 121before each correction is attempted. 122It should be noted that some of the corrective actions which are not 123correctable under the 124.Fl p 125option will result in some loss of data. 126The amount and severity of data lost may be determined from the diagnostic 127output. 128The default action for each consistency correction 129is to wait for the operator to respond 130.Li yes 131or 132.Li no . 133If the operator does not have write permission on the file system 134.Nm 135will default to a 136.Fl n 137action. 138.Pp 139The following flags are interpreted by 140.Nm : 141.Bl -tag -width indent 142.It Fl F 143Determine whether the file system needs to be cleaned immediately 144in foreground, or if its cleaning can be deferred to background. 145To be eligible for background cleaning it must have been running 146with soft updates, not have been marked as needing a foreground check, 147and be mounted and writable when the background check is to be done. 148If these conditions are met, then 149.Nm 150exits with a zero exit status. 151Otherwise it exits with a non-zero exit status. 152If the file system is clean, 153it will exit with a non-zero exit status so that the clean status 154of the file system can be verified and reported during the foreground 155checks. 156Note that when invoked with the 157.Fl F 158flag, no cleanups are done. 159The only thing that 160.Nm 161does is to determine whether a foreground or background 162check is needed and exit with an appropriate status code. 163.It Fl B 164A check is done on the specified and possibly active file system. 165The set of corrections that can be done is limited to those done 166when running in preen mode (see the 167.Fl p 168flag). 169If unexpected errors are found, 170the file system is marked as needing a foreground check and 171.Nm 172exits without attempting any further cleaning. 173.It Fl b 174Use the block specified immediately after the flag as 175the super block for the file system. 176An alternate super block is usually located at block 32 for UFS1, 177and block 160 for UFS2. 178.It Fl C 179Check if file system was dismounted cleanly. 180If so, skip file system checks (like "preen"). 181However, if the file system was not cleanly dismounted, do full checks, 182as if 183.Nm 184was invoked without 185.Fl C . 186.It Fl c 187Convert the file system to the specified level. 188Note that the level of a file system can only be raised. 189There are currently four levels defined: 190.Bl -tag -width indent 191.It 0 192The file system is in the old (static table) format. 193.It 1 194The file system is in the new (dynamic table) format. 195.It 2 196The file system supports 32-bit uid's and gid's, 197short symbolic links are stored in the inode, 198and directories have an added field showing the file type. 199.It 3 200If maxcontig is greater than one, 201build the free segment maps to aid in finding contiguous sets of blocks. 202If maxcontig is equal to one, delete any existing segment maps. 203.El 204.Pp 205In interactive mode, 206.Nm 207will list the conversion to be made 208and ask whether the conversion should be done. 209If a negative answer is given, 210no further operations are done on the file system. 211In preen mode, 212the conversion is listed and done if 213possible without user interaction. 214Conversion in preen mode is best used when all the file systems 215are being converted at once. 216The format of a file system can be determined from the 217first line of output from 218.Xr dumpfs 8 . 219.Pp 220This option implies the 221.Fl f 222flag. 223.It Fl f 224Force 225.Nm 226to check 227.Sq clean 228file systems when preening. 229.It Fl m 230Use the mode specified in octal immediately after the flag as the 231permission bits to use when creating the 232.Pa lost+found 233directory rather than the default 1777. 234In particular, systems that do not wish to have lost files accessible 235by all users on the system should use a more restrictive 236set of permissions such as 700. 237.It Fl n 238Assume a no response to all questions asked by 239.Nm 240except for 241.Ql CONTINUE? , 242which is assumed to be affirmative; 243do not open the file system for writing. 244.It Fl p 245Preen file systems (see above). 246.It Fl r 247Free up excess unused inodes. 248Decreasing the number of preallocated inodes reduces the 249running time of future runs of 250.Nm 251and frees up space that can allocated to files. 252The 253.Fl r 254option is ignored when running in preen mode. 255.It Fl y 256Assume a yes response to all questions asked by 257.Nm ; 258this should be used with great caution as this is a free license 259to continue after essentially unlimited trouble has been encountered. 260.El 261.Pp 262Inconsistencies checked are as follows: 263.Pp 264.Bl -enum -compact 265.It 266Blocks claimed by more than one inode or the free map. 267.It 268Blocks claimed by an inode outside the range of the file system. 269.It 270Incorrect link counts. 271.It 272Size checks: 273.Bl -item -offset indent -compact 274.It 275Directory size not a multiple of DIRBLKSIZ. 276.It 277Partially truncated file. 278.El 279.It 280Bad inode format. 281.It 282Blocks not accounted for anywhere. 283.It 284Directory checks: 285.Bl -item -offset indent -compact 286.It 287File pointing to unallocated inode. 288.It 289Inode number out of range. 290.It 291Directories with unallocated blocks (holes). 292.It 293Dot or dot-dot not the first two entries of a directory 294or having the wrong inode number. 295.El 296.It 297Super Block checks: 298.Bl -item -offset indent -compact 299.It 300More blocks for inodes than there are in the file system. 301.It 302Bad free block map format. 303.It 304Total free block and/or free inode count incorrect. 305.El 306.El 307.Pp 308Orphaned files and directories (allocated but unreferenced) are, 309with the operator's concurrence, reconnected by 310placing them in the 311.Pa lost+found 312directory. 313The name assigned is the inode number. 314If the 315.Pa lost+found 316directory does not exist, it is created. 317If there is insufficient space its size is increased. 318.Pp 319The full foreground 320.Nm 321checks for many more problems that may occur after an 322unrecoverable disk write error. 323Thus, it is recommended that you perform foreground 324.Nm 325on your systems periodically and whenever you encounter 326unrecoverable disk write errors or file-system\-related panics. 327.Sh FILES 328.Bl -tag -width /etc/fstab -compact 329.It Pa /etc/fstab 330contains default list of file systems to check. 331.El 332.Sh EXIT STATUS 333.Ex -std 334.Pp 335If the option 336.Fl F 337is used, 338.Nm 339exits 7 if the file system is clean. 340.Sh DIAGNOSTICS 341The diagnostics produced by 342.Nm 343are fully enumerated and explained in Appendix A of 344.Rs 345.%T "Fsck \- The UNIX File System Check Program" 346.Re 347.Sh SEE ALSO 348.Xr fs 5 , 349.Xr fstab 5 , 350.Xr fsck 8 , 351.Xr fsdb 8 , 352.Xr newfs 8 , 353.Xr reboot 8 354