How to format a USB flash drive?

You can use Disks it's installed by default and easy to use.

• 1st: Click on the Dash icon
• 2nd: Search for "Disks"
• 3rd: Click on Disks

The application will shows up:

• 1st: Choose the USB flash drive
• 2nd: Click on the "gear" icon and choose "Format"

This little window will appear, just choose the option you want and click on Format...:

In Ubuntu there are many methods by which you can format your pen drive.

1 With the Disks utility

see the video

This is the simplest way.

2 With GParted

see the video

You can install it

• from Ubuntu Software Center or

• on the command-line:

  sudo apt install gparted
  

3 On the command line

see the video

1. To show the USB drive among all storage partitions and volumes on your computer use:

   lsblk
   

   You can also use:

   df
   

2. Suppose it may be /dev/sdy1. Unmount it with:

   sudo umount /dev/sdy1
   

3. To format drive with the FAT32 file system format:

   sudo mkfs.vfat -F 32 /dev/sdy1
   

   To set a file system label for your pen drive in the process:

   sudo mkfs.vfat -F 32 -n 'name_for_your_pendrive' /dev/sdy1
   

   You must include the -F 32 part to specify the FAT size, it is not 32 by default in ubuntu 19.10. For more info see man mkfs.fat.

The Command-Line Way

In case you can't get your device formatted from the GUI, try this way.

1. Open the Terminal (Ctrl+Alt+T)

2. List your block storage devices by issuing the command lsblk
   Then identify your pen drive by it's SIZE. In my case its /dev/sdb

   

3. Erase everything in the pen drive (This step is Optional):

   sudo dd status=progress if=/dev/zero of=/dev/sdb bs=4k && sync  
   

   Replace /dev/sdb with your corresponding device.

   Type very carefully this name or your may end up erasing one of your other disks. This will take some time. (option status=progress is not mandatory but provide you some feedback)

   It will pretend to be stuck. Just be patient.

   for example:

   dd if=/dev/zero of=/dev/sdb bs=4k && sync
   dd: error writing '/dev/sdb': No space left on device
   
   1984257+0 records in
   1984256+0 records out
   8127512576 bytes (8.1 GB) copied, 1236.37 s, 6.6 MB/s
   

4. Make a new partition table in the device:

   sudo fdisk /dev/sdb
   

   Then press letter o to create a new empty DOS partition table.

5. Make a new partition:

   • Press letter n to add a new partition. You will be prompted for the size of the partition. Making a primary partition when prompted, if you are not sure.

   • Then press letter w to write table to disk and exit.

6. Format your new partition.

   • See your new partition label with the command lsblk
     In my case it is /dev/sdb1. Once again pay attention to this name as there will not be any protection to prevent you to erase an other disk.

   

   • Issue the command below to format the new volume:

     sudo mkfs.vfat /dev/sdb1  
     

     Please replace /dev/sdb1 with your corresponding device.

   • Eject the device:

     sudo eject /dev/sdb