USB memory for RaspberryPi

1. Find the USB memory stick

sudo ls /dev/sd*
Then you find (for example) /dev/sda /dev/sda1

2. Repartition and format

sudo fdisk /dev/sda
p (print partition table)
d
n p 1 (use default sector nubers to use entire memory)
w

sudo mkfs.ext4 /dev/sda1 -L stickan
sudo tune2fs -o discard /dev/sda1

3. Create mount point

sudo mkdir /mnt/usb

4. Mount the usb stick

sudo nano /etc/fstab
Add:
/dev/sda1 /mnt/usb ext4 defaults,noatime 0 1
sudo mount /dev/sda1

5. (optional) move data directories

Move directory to usb
sudo mv /srv /mnt/usb
make link from the original location
sudo ln -s /mnt/usb/srv /