FSCK_MSDOSFS(8)         FreeBSD System Manager's Manual        FSCK_MSDOSFS(8)

NAME
     fsck_msdosfs - DOS/Windows (FAT) file system consistency checker

SYNOPSIS
     fsck_msdosfs -p [-Cf] filesystem ...
     fsck_msdosfs [-CMny] filesystem ...

DESCRIPTION
     The fsck_msdosfs utility verifies and repairs FAT file systems (more
     commonly known as DOS file systems).

     The first form of fsck_msdosfs preens the specified file systems.  It is
     normally started by fsck(8) run from /etc/rc during automatic reboot,
     when a FAT file system is detected.  When preening file systems,
     fsck_msdosfs will fix common inconsistencies non-interactively.  If more
     serious problems are found, fsck_msdosfs does not try to fix them,
     indicates that it was not successful, and exits.

     The second form of fsck_msdosfs checks the specified file systems and
     tries to repair all detected inconsistencies, requesting confirmation
     before making any changes.

     The options are as follows:

     -C      Compatibility with the corresponding fsck(8) option (skip check
             if clean), defined to no-op.

     -F      Compatibility with the wrapper fsck(8) which seeks to determine
             whether the file system needs to be cleaned immediately in
             foreground, or if its cleaning can be deferred to background.
             FAT (MS-DOS) file systems must always be cleaned in the
             foreground.  A non-zero exit code is always returned for this
             option.

     -M      Causes fsck_msdosfs to not use mmap(2) when checking a FAT32 file
             system.  This option is mainly for debugging purposes and is not
             normally necessary.  The fsck_msdosfs utility will automatically
             fall back to use a simple LRU cache of 4 MiB when it failed to
             perform mmap(2), or when -M is specified.

     -f      Force fsck_msdosfs to check "clean" file systems when preening.

     -n      Causes fsck_msdosfs to assume "no" as the answer to all operator
             questions, except "CONTINUE?".

     -p      Preen the specified file systems.

     -y      Causes fsck_msdosfs to assume "yes" as the answer to all operator
             questions.

SEE ALSO
     fsck(8), fsck_ffs(8), mount_msdosfs(8)

HISTORY
     The fsck_msdosfs utility appeared in NetBSD 1.2.  fsck_msdosfs first
     appeared in FreeBSD 4.4.

BUGS
     The fsck_msdosfs utility is currently under development.

FreeBSD 13.1-RELEASE-p6         January 6, 2020        FreeBSD 13.1-RELEASE-p6