Mount USB drive in RPi2

By default, RPi2 limits power supply of USB ports to 0.6A, while most USB drives require more than that. This is why most USB drives cannot be used with RPi2 without external power supply to RPi2. Luckily, given that you have decent power supply (ie I have 2A charger), you can increase USB port max current, by editing `/boot/config.txt`.

IMPORTANT!!! RPi2 allows max 1.2A current through all 4 USB ports combined, so don’t even think about plugging two USB drives!!! This is because the maximum power allowed into the RPi2 is limited to 2A by the fuse (F1) so if one of your USB device draw 1A, then that leaves 1A for the RPi + GPIO + remaining USB devices.

First, check if your drive can be detected without tweaking
[bash]
sudo blkid
[/bash]

If you see only mmcblk0 entries, this means that your drive is not recognised.
[bash]
/dev/mmcblk0p1: …
/dev/mmcblk0p2: …
/dev/mmcblk0: PTUUID="d2fd971c" PTTYPE="dos"
[/bash]

Add max_usb_current=1 to /boot/config.txt:

Reboot and check if your USB drive is visible after restart:
[bash]
sudo reboot
sudo blkid
[/bash]

Now, you should see new entry:
[bash]
/dev/mmcblk0p1: …
/dev/mmcblk0p2: …
/dev/mmcblk0: PTUUID="d2fd971c" PTTYPE="dos"
/dev/sda1: LABEL="turo"…
[/bash]

And you should be able to mount it:
[bash]
sudo mkdir -p /media/turo
sudo mount /dev/sda1 /media/turo
[/bash]

Inspired by www.htpcguides.com and www.raspberrypi.org/forums.