1.\" $NetBSD: fsck_msdos.8,v 1.9 1997/10/17 11:19:58 ws Exp $ 2.\" 3.\" Copyright (C) 1995 Wolfgang Solfrank 4.\" Copyright (c) 1995 Martin Husemann 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.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd January 6, 2020 29.Dt FSCK_MSDOSFS 8 30.Os 31.Sh NAME 32.Nm fsck_msdosfs 33.Nd DOS/Windows (FAT) file system consistency checker 34.Sh SYNOPSIS 35.Nm 36.Fl p 37.Op Fl Cf 38.Ar filesystem ... 39.Nm 40.Op Fl CMny 41.Ar filesystem ... 42.Sh DESCRIPTION 43The 44.Nm 45utility verifies and repairs 46.Tn FAT 47file systems (more commonly known 48as 49.Tn DOS 50file systems). 51.Pp 52The first form of 53.Nm 54preens the specified file systems. 55It is normally started by 56.Xr fsck 8 57run from 58.Pa /etc/rc 59during automatic reboot, when a FAT file system is detected. 60When preening file systems, 61.Nm 62will fix common inconsistencies non-interactively. 63If more serious problems are found, 64.Nm 65does not try to fix them, indicates that it was not 66successful, and exits. 67.Pp 68The second form of 69.Nm 70checks the specified file systems and tries to repair all 71detected inconsistencies, requesting confirmation before 72making any changes. 73.Pp 74The options are as follows: 75.Bl -tag -width indent 76.It Fl C 77Compatibility with the corresponding 78.Xr fsck 8 79option (skip check if clean), defined to no-op. 80.It Fl F 81Compatibility with the wrapper 82.Xr fsck 8 83which seeks to determine whether the file system needs to be cleaned 84immediately in foreground, or if its cleaning can be deferred to background. 85FAT (MS-DOS) file systems must always be cleaned in the foreground. 86A non-zero exit code is always returned for this option. 87.It Fl M 88Causes 89.Nm 90to not use 91.Xr mmap 2 92when checking a FAT32 file system. 93This option is mainly for debugging purposes and is not normally necessary. 94The 95.Nm 96utility will automatically fall back to use a simple LRU cache of 4 MiB 97when it failed to perform 98.Xr mmap 2 , 99or when 100.Fl M 101is specified. 102.It Fl f 103Force 104.Nm 105to check 106.Dq clean 107file systems when preening. 108.It Fl n 109Causes 110.Nm 111to assume 112.Dq Li no 113as the answer to all operator 114questions, except 115.Dq Li CONTINUE? . 116.It Fl p 117Preen the specified file systems. 118.It Fl y 119Causes 120.Nm 121to assume 122.Dq Li yes 123as the answer to all operator questions. 124.El 125.Sh SEE ALSO 126.Xr fsck 8 , 127.Xr fsck_ffs 8 , 128.Xr mount_msdosfs 8 129.Sh HISTORY 130The 131.Nm 132utility appeared in 133.Nx 1.2 . 134.Nm 135first appeared in 136.Fx 4.4 . 137.Sh BUGS 138The 139.Nm 140utility is 141.Ud 142