---
name: "msdos.util"
section: "8"
platform: "macos"
package: "msdosfs"
version: "788.100.31"
release: "macOS 26.5"
platforms: ["macos"]
url: "https://new.carta.tech/msdos.util"
---

# msdos.util(8)

DOS/Windows (FAT) file system utility

## NAME

**msdos.util** – DOS/Windows (FAT) file system utility

## SYNOPSIS

**msdos.util** **-m** *mountflag1* *mountflag2* *mountflag3* *mountflag4* *device* *node*

**msdos.util** **-p** *mountflag1* *mountflag2* *mountflag3* *mountflag4* *device*

**msdos.util** **-u** *device*

**msdos.util** **-k** *device*

**msdos.util** **-n** *device* *name*

## DESCRIPTION

The **msdos.util** command supports the mounting, probing, and unmounting of FAT file systems.

Options:

- **-m** *mountflag1* *mountflag2* *mountflag3* *mountflag4*

  mount

- **-n**

  set name

- **-p** *mountflag1* *mountflag2* *mountflag3* *mountflag4*

  probe for mounting

- **-u**

  unmount

- **-k**

  print volume UUID

*mountflags* above are either:

- *removable* or *fixed*

- *readonly* or *writeable*

- *suid* or *nosuid*

- *dev* or *nodev*

FAT volumes do not actually have a volume UUID. They have an optional 4-byte volume ID. If a volume has an ID, then it will be converted to a version 3 UUID using MD5 to checksum the kFSUUIDNamespaceSHA1 UUID folowed by the volume ID.

For the **-k** option, if the volume has a volume ID, the exit status will be 253 and the UUID will be printed to standard out, without any trailing newline. Otherwise, if the volume appears to be FAT, the exit status will be 255. If the volume does not appear to be FAT, the exit status will be 254.

## FILES

*/System/Library/Filesystems/msdos.fs/Contents/Resources/msdos.util*

## SEE ALSO

[diskarbitrationd(8)](/diskarbitrationd/8.md)

## HISTORY

Derived from the Openstep Workspace Manager file system utility programs.