create fat filesystem with linux

1. for gentoo users, emerge the package dosfstools

2. figure out the device name for you disk

If it a usb drive, I run "ls /dev/sd*" before and after I pug it in and see what changed. Otherwise I run cfdisk against a disk to verify geometry to indentify the correct drive. Usually my drives are of different sizes, so that method works well.

3. Use fdisk to create the partition:

here I am going to create a 250GB partion on my empty 1TB drive

example

# fdisk /dev/sdf                                                                                             ~

Welcome to fdisk (util-linux 2.24).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table.

Created a new DOS disklabel with disk identifier 0x906eeaeb.

Command (m for help): p
Disk /dev/sdf: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x906eeaeb

Command (m for help): n

Partition type:
  p   primary (0 primary, 0 extended, 4 free)
  e   extended
Select (default p): p
Partition number (1-4, default 1): 
First sector (2048-1953525167, default 2048): 
Last sector, +sectors or +size{K,M,G,T,P} (2048-1953525167, default 1953525167): +250G

Created a new partition 1 of type 'Linux' and of size 250 GiB.
<bar>Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): b
If you have created or modified any DOS 6.x partitions, please see the fdisk documentation for additional information.
Changed type of partition 'Linux' to 'W95 FAT32'.

Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

2. Create / format the filesystem

# mkfs.vfat -F 32 /dev/sdf1