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
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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
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26.\" $FreeBSD$
27.\"
28.Dd February 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 f
38.Ar filesystem ...
39.Nm
40.Op Fl fMny
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 F
77Compatibility with the wrapper
78.Xr fsck 8
79which seeks to determine whether the file system needs to be cleaned
80immediately in foreground, or if its cleaning can be deferred to background.
81FAT (MS-DOS) file systems must always be cleaned in the foreground.
82A non-zero exit code is always returned for this option.
83.It Fl M
84Causes
85.Nm
86to not use
87.Xr mmap 2
88when checking a FAT32 file system.
89This option is mainly for debugging purposes and is not normally necessary.
90The
91.Nm
92utility will automatically fall back to use a simple LRU cache of 4 MiB
93when it failed to perform
94.Xr mmap 2 ,
95or when
96.Fl M
97is specified.
98.It Fl f
99This option is ignored by
100.Nm ,
101and is present only for compatibility with programs that
102check other file system types for consistency, such as
103.Xr fsck_ffs 8 .
104.It Fl n
105Causes
106.Nm
107to assume
108.Dq Li no
109as the answer to all operator
110questions, except
111.Dq Li CONTINUE? .
112.It Fl p
113Preen the specified file systems.
114.It Fl y
115Causes
116.Nm
117to assume
118.Dq Li yes
119as the answer to all operator questions.
120.El
121.Sh SEE ALSO
122.Xr fsck 8 ,
123.Xr fsck_ffs 8 ,
124.Xr mount_msdos 8
125.Sh HISTORY
126The
127.Nm
128utility appeared in
129.Nx 1.2 .
130.Nm
131first appeared in
132.Fx 4.4 .
133.Sh BUGS
134The
135.Nm
136utility is currently under development.
137