This version of this document is no longer maintained. For the latest documentation, see http://www.qnx.com/developers/docs.

mkdosfs

Format a DOS (FAT-12/16/32) filesystem (QNX Neutrino)

Syntax:

mkdosfs [-C|c size] [-e number]
        [-F type] [-f number] [-h number] 
        [-I vol_id] [-L vol_label] [-m media] 
        [-O oem_label] [-R|r] [-S size] [-s size] 
        device | mountpoint | file

Runs on:

Neutrino

Options:

-C size

Minimum default cluster size. Don't specify both -C and -c.

-c size

Cluster size for the filesystem; the default is determined by disk geometry. Don't specify both -c and -C.

-e number

Number of root directory entries (FAT12/16 only); the default is 512.

-F type

The FAT type (12, 16, or 32).

-f number

Set the number of FAT tables to write; the default is 2.

-h number

The number of "hidden sectors"; the default is determined by disk geometry.

-I vol_id

Set the volume ID/serial number; the default is based on the current time.

-L vol_label

Specify a volume label; the default is none.

-m media

Media descriptor byte; the default is 0xF0 or, if there are hidden sectors, 0xF8.

-O oem_label

Set the OEM label; the default is:

MSDOS5.0

For a FAT12/FAT16 filesystem.

MSWIN4.1

For a FAT32 filesystem.

-R

Preserve the size and content of existing reserved sectors (reformat).

-r

The number of "reserved sectors"; the default is determined by FAT type.

-S size

Sector size for the filesystem; the default is determined by disk geometry.

-s size

Set the size (number of sectors) in the filesystem; the default is determined by disk geometry.

device

The device name to host the DOS filesystem (e.g. /dev/hd0t11).

mountpoint

The mountpoint of the DOS filesystem (e.g. /fs/hd0-dos).

file

A regular file to contain the DOS filesystem image.

Description:

The mkdosfs utility formats a DOS filesystem on the specified target (typically a disk device or partition).

If you don't specify essential user options such as FAT type and cluster size, mkdosfs formats the DOS filesystem using the most suitable options for the size and disk geometry of the host. You can override this default auto-configuration and force a particular format to be used by setting the options you need.

Examples:

# mkdosfs /dev/hd0t6

Format complete: FAT16 (4096-byte clusters), 201888 kB available.

Exit status:

0

The filesystem was constructed without error.

1

The filesystem wasn't constructed. This may be due to an error or inconsistency with the user options or because of a nonrecoverable error, such as disk I/O or insufficient memory.

Contributing author:

Robert Nordier

License:

This utility is based on software from Robert Nordier; please see mkdosfs in the appendix Third-Party Copyright Notices.

Caveats:

The mkdosfs utility destroys or overwrites any existing filesystem on the target.

See also:

chkdosfs, devb-eide, fs-dos.so, mount, umount