The
fsck_msdos utility verifies and repairs FAT filesystems (more commonly known as DOS filesystems).
The first form of
fsck_msdos preens the specified filesystems. It is normally started by
fsck(8) run from
/etc/rc during automatic reboot, when a FAT filesystem is detected. When preening file systems,
fsck_msdos will fix common inconsistencies non-interactively. If more serious problems are found,
fsck_msdos does not try to fix them, indicates that it was not successful, and exits.
The second form of
fsck_msdos checks the specified file systems and tries to repair all detected inconsistencies, requesting confirmation before making any changes.
The options are as follows:
-f
This option is ignored by
fsck_msdos, and is present only for compatibility with programs that check other file system types for consistency, such as
fsck_ffs(8).
-n
Causes fsck_msdos to assume no as the answer to all operator questions, except “CONTINUE?”.
-p
Preen the specified filesystems.
-x snap-backup
Use a snapshot with
snap-backup as backup to check a read-write mounted filesystem. Must be used with
-n. See
fss(4) for more details. The point is to check an internally-consistent version of the filesystem to find out if it is damaged; on failure one should unmount the filesystem and repair it.
-y
Causes fsck_msdos to assume yes as the answer to all operator questions.