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 April 27, 2011 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 BEFfnpry 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 B 143A check is done on the specified and possibly active file system. 144The set of corrections that can be done is limited to those done 145when running in preen mode (see the 146.Fl p 147flag). 148If unexpected errors are found, 149the file system is marked as needing a foreground check and 150.Nm 151exits without attempting any further cleaning. 152.It Fl E 153Clear unallocated blocks, notifying the underlying device that they 154are not used and that their contents may be discarded. 155This is useful for filesystems which have been mounted on systems 156without TRIM support, or with TRIM support disabled, as well as 157filesystems which have been copied from one device to another. 158.Pp 159See the 160.Fl E 161and 162.Fl t 163flags of 164.Xr newfs 8 , 165and 166the 167.Fl t 168flag of 169.Xr tunefs 8 . 170.It Fl F 171Determine whether the file system needs to be cleaned immediately 172in foreground, or if its cleaning can be deferred to background. 173To be eligible for background cleaning it must have been running 174with soft updates, not have been marked as needing a foreground check, 175and be mounted and writable when the background check is to be done. 176If these conditions are met, then 177.Nm 178exits with a zero exit status. 179Otherwise it exits with a non-zero exit status. 180If the file system is clean, 181it will exit with a non-zero exit status so that the clean status 182of the file system can be verified and reported during the foreground 183checks. 184Note that when invoked with the 185.Fl F 186flag, no cleanups are done. 187The only thing that 188.Nm 189does is to determine whether a foreground or background 190check is needed and exit with an appropriate status code. 191.It Fl b 192Use the block specified immediately after the flag as 193the super block for the file system. 194An alternate super block is usually located at block 32 for UFS1, 195and block 160 for UFS2. 196.It Fl C 197Check if file system was dismounted cleanly. 198If so, skip file system checks (like "preen"). 199However, if the file system was not cleanly dismounted, do full checks, 200as if 201.Nm 202was invoked without 203.Fl C . 204.It Fl c 205Convert the file system to the specified level. 206Note that the level of a file system can only be raised. 207There are currently four levels defined: 208.Bl -tag -width indent 209.It 0 210The file system is in the old (static table) format. 211.It 1 212The file system is in the new (dynamic table) format. 213.It 2 214The file system supports 32-bit uid's and gid's, 215short symbolic links are stored in the inode, 216and directories have an added field showing the file type. 217.It 3 218If maxcontig is greater than one, 219build the free segment maps to aid in finding contiguous sets of blocks. 220If maxcontig is equal to one, delete any existing segment maps. 221.El 222.Pp 223In interactive mode, 224.Nm 225will list the conversion to be made 226and ask whether the conversion should be done. 227If a negative answer is given, 228no further operations are done on the file system. 229In preen mode, 230the conversion is listed and done if 231possible without user interaction. 232Conversion in preen mode is best used when all the file systems 233are being converted at once. 234The format of a file system can be determined from the 235first line of output from 236.Xr dumpfs 8 . 237.Pp 238This option implies the 239.Fl f 240flag. 241.It Fl f 242Force 243.Nm 244to check 245.Sq clean 246file systems when preening. 247.It Fl m 248Use the mode specified in octal immediately after the flag as the 249permission bits to use when creating the 250.Pa lost+found 251directory rather than the default 1777. 252In particular, systems that do not wish to have lost files accessible 253by all users on the system should use a more restrictive 254set of permissions such as 700. 255.It Fl n 256Assume a no response to all questions asked by 257.Nm 258except for 259.Ql CONTINUE? , 260which is assumed to be affirmative; 261do not open the file system for writing. 262.It Fl p 263Preen file systems (see above). 264.It Fl r 265Free up excess unused inodes. 266Decreasing the number of preallocated inodes reduces the 267running time of future runs of 268.Nm 269and frees up space that can allocated to files. 270The 271.Fl r 272option is ignored when running in preen mode. 273.It Fl y 274Assume a yes response to all questions asked by 275.Nm ; 276this should be used with great caution as this is a free license 277to continue after essentially unlimited trouble has been encountered. 278.El 279.Pp 280Inconsistencies checked are as follows: 281.Pp 282.Bl -enum -compact 283.It 284Blocks claimed by more than one inode or the free map. 285.It 286Blocks claimed by an inode outside the range of the file system. 287.It 288Incorrect link counts. 289.It 290Size checks: 291.Bl -item -offset indent -compact 292.It 293Directory size not a multiple of DIRBLKSIZ. 294.It 295Partially truncated file. 296.El 297.It 298Bad inode format. 299.It 300Blocks not accounted for anywhere. 301.It 302Directory checks: 303.Bl -item -offset indent -compact 304.It 305File pointing to unallocated inode. 306.It 307Inode number out of range. 308.It 309Directories with unallocated blocks (holes). 310.It 311Dot or dot-dot not the first two entries of a directory 312or having the wrong inode number. 313.El 314.It 315Super Block checks: 316.Bl -item -offset indent -compact 317.It 318More blocks for inodes than there are in the file system. 319.It 320Bad free block map format. 321.It 322Total free block and/or free inode count incorrect. 323.El 324.El 325.Pp 326Orphaned files and directories (allocated but unreferenced) are, 327with the operator's concurrence, reconnected by 328placing them in the 329.Pa lost+found 330directory. 331The name assigned is the inode number. 332If the 333.Pa lost+found 334directory does not exist, it is created. 335If there is insufficient space its size is increased. 336.Pp 337The full foreground 338.Nm 339checks for many more problems that may occur after an 340unrecoverable disk write error. 341Thus, it is recommended that you perform foreground 342.Nm 343on your systems periodically and whenever you encounter 344unrecoverable disk write errors or file-system\-related panics. 345.Sh FILES 346.Bl -tag -width /etc/fstab -compact 347.It Pa /etc/fstab 348contains default list of file systems to check. 349.El 350.Sh EXIT STATUS 351.Ex -std 352.Pp 353If the option 354.Fl F 355is used, 356.Nm 357exits 7 if the file system is clean. 358.Sh DIAGNOSTICS 359The diagnostics produced by 360.Nm 361are fully enumerated and explained in Appendix A of 362.Rs 363.%T "Fsck \- The UNIX File System Check Program" 364.Re 365.Sh SEE ALSO 366.Xr fs 5 , 367.Xr fstab 5 , 368.Xr fsck 8 , 369.Xr fsdb 8 , 370.Xr newfs 8 , 371.Xr reboot 8 372