Manual page and help for the mkfs.fat linux command. You can use mkfs.fat to create an MS-DOS file system under Linux on a device (usually a disk partition). The "DEVICE" parameter is a special file that specifies access to the device under operation (eg / dev / sdXX). Must be entered. The "BLOCK-COUNT" option allows you to specify the number of blocks on the device. When you leave, mkfs.fat automatically determines the size of the file system.