MKFATFS

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
BUGS
AUTHORS
AVAILABILITY

NAME

mkfatfs − create a FAT file system

SYNOPSIS

mkfatfs [options] device

DESCRIPTION

mkfatfs is used to create a FAT file system on a device (usually a disk or flash partition). device is the special file corresponding to the device (e.g. /dev/sdXX, /dev/block/mmcblk1p1).

OPTIONS

Below is a summary of all the options that mkfatfs accepts. Nearly all options have two equivalent names. The short name is preceded by and the long name is preceded by −−.

−f, −−force

Allow formatting a FAT volume for which the physical sector size cannot be automatically detected (for example an image file).

−l, −−volume−label STRING

Set the volume label for the filesystem. The volume label can be up to 11 ASCII units long, i.e. in most cases 11 bytes.

−i, −−volume−id STRING

Sets the volume-id for the volume to STRING.

−r, −−rootdir−entries NUMBER

Set the count of 32 bytes directory entries in the root directory to NUMBER. For FAT32 volumes this value is ignored and set to zero. For FAT 12/16 volume the default value is 512.

−f, −−fat−type FATBITS

Set the FAT bits for the volume to FATBITS. The legal values for this field are [12, 16, 32].

−S, −−sector−size SIZE

Set the volume sector size (in bytes) to SIZE. The default is to detect sector size automatically. Note: This option should probably never be used when formatting devices directly as most FAT drivers won’t be able to use a FAT volume where the volume sector size doesn’t match the physical sector size.

−s, −−sectors−per−cluster VALUE

Set the volume cluster size (in bytes) to VALUE * sector_size. The default value is calculated dynamically depending on FAT type (FAT 12/16/32) and the size of the volume. The legal values for this field are [1, 2, 4, 8, 16, 32, 64, 128], such that VALUE * sector_size does not exceed 32K.

−v, −−verbose

Makes mkfatfs emit certain status messages related to the formatting process.

−−sda−strict

Forces the formatted volume to adhere to SD Association recommendations.

−−sda−whole

Performs a whole device formatting, including partition table, according to the SD Association recommendations. This option should only be used with whole devices (e.g. /dev/mmcblk0) and never partitions (e.g. /dev/mmcblk0p1).

−−sda−relax

Relaxes sanity checks for −−sda−strict and −−sda−whole to allow formatting devices that don’t comply to the size specifications of SD cards to be formatted according to the SD Association guidelines.

NOTE: This option is only a modifier to −−sda−strict and −−sda−whole and does not do anything on its own.

−−discard

This option sends a ’discard’ command, like TRIM, to the device which will zero all data on it.

BUGS

If you find a bug please send an email describing the problem to fat-support@tuxera.com.

AUTHORS

mkfatfs was written by Sougata Santra, Tuxera Inc.

AVAILABILITY

mkfatfs is part of the Tuxera FATprogs package.