Add a USB drive to a Raspberry Pi (Raspbian)

rpi-add-usb

Find USB device ...

    $ ls -l /dev/disk/by-uuid/
    total 0
    lrwxrwxrwx 1 root root 10 Feb  9 01:26 093F-C00F -> ../../sda1
    lrwxrwxrwx 1 root root 15 Feb  9 01:26 2ab3f8e1-7dc6-43f5-b0db-dd8364731d4e -> ../../mmcblk0p2
    lrwxrwxrwx 1 root root 15 Feb  9 01:26 5203-D7B4 -> ../../mmcblk0p1

The one we are looking for is "/sda"

Now create a mount point ...

    $ sudo mkdir /media/usb
    $ sudo chown -R <USER>:<GROUP> /media/usb

And now manually mount the drive ...

    $ sudo mount /dev/sda1 /media/usb -o uid=<USER>,gid=<GROUP>
    
This will mount the drive so that the specified ordinary user can write to it. Omitting the
"-o uid=<USER>,gid=<GROUP>" would only allow root to write.

To unmount ...

    $ umount /media/usb

To set up automount, need to add this line to /etc/fstab ...

    UUID=093F-C00F /media/usb vfat auto,nofail,noatime,users,rw,uid=<USER>,gid=<GROUP> 0 0

The UUID value needs to match the one from the initial "ls" command, the "nofail" option allows the boot
process to proceed if the drive is not plugged in. The "noatime" option stops the file access time being
updated every time a file is read from the USB stick (improves performance).

To unmount a drive added via automount, need to use sudo ...

    $ sudo umount /media/usb