Format and use USB key

Tests have been done with Linux Mint 21.2 but the process does not depend on the distribution.

• Plug the key.
• Once detected, Nemo or any other “file explorer” opens.
• CTRL + ALT + T to open a terminal.

lsblk                                       # No need to be root
                                            # You see sdb1 or sdb1 and sdb2 (my case)
                                            # They are mounted on /media/philippe/xxxxx and /media/philippe/yyyyyyy
umount /dev/sdb1                            #
umount /dev/sdb2
lsblk                                       # No mounting point anymore

I suppose the USB stick is under /dev/sdb

If the USB stick must be bootable

• Create a partition table, skip this step otherwise

sudo fdisk /dev/sdb
g                                           # Create GPT - Globally Unique Identifier Partition Table

I want to create 2 partitions

• If fdisk is not already in use, run it : sudo fdisk /dev/sdb
• The letters below (p, d…) are the key to use once under fdisk

p                                           # print partitions. Double check you're on the USB and NOT you main drive
d                                           # delete partition
n                                           # new partition (p,1,2048,+200M)
n                                           # new partition (keep default values: p...)
p                                           # double check
w                                           # write and quit fdisk

Create a filesystem

sudo fdisk -l                               # Shows the 2 partitions sdb1 et sdb2
sudo mkfs.ext4 /dev/sdb1
sudo mkfs.ext4 /dev/sdb2
sudo fsck /dev/sdb1                         # checking
sudo fsck /dev/sdb2

Only if you’re paranoid, skip otherwise

sudo dd if=/dev/zero of=/dev/sdb1 bs=1M     # write 0
sudo shred -n 3 -z /dev/sdb1                # 3 times, zeroes the partition

If one day you want to remove the GPT

sudo gdisk /dev/sdb
?                                          # To see the menu
i                                          # To check partitions details information
                                           # Use x then z options to zap the GPT data structure

At this stage you can unplug and plug the key or…

Mount the USB key

sudo mkdir /media/usb1                              # The dirs belong to root
sudo mkdir /media/usb2                              # Remember the Alamo and the fact that I have 2 partition on the stick
sudo chown -R philippe:philippe /media/usb1         # change ownership
sudo chown -R philippe:philippe /media/usb2
sudo mount /dev/sdb1 /media/usb1
sudo mount /dev/sdb2 /media/usb2

• Use the key as philippe

Unmount the USB key

sudo umount /media/usb1
sudo umount /media/usb2
sudo rmdir /media/usb1
sudo rmdir /media/usb2

• Unplug the USB key