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Adafruit-Pi-ExternalRoot-helper

A shell script for configuring an external USB drive as root filesystem on a Raspberry Pi running Raspbian. It's a companion to Using an External Drive as a Raspberry Pi Root Filesystem, which you should read first.

Using adafruit-pi-externalroot-helper

First, read the tutorial.

On a Raspberry Pi running Raspbian, with a USB-connected storage device you wish to use for your root filesystem:

git clone git@github.com:adafruit/Adafruit-Pi-ExternalRoot-Helper.git
cd Adafruit-Pi-ExternalRoot-Helper
sudo ./adafruit-pi-externalroot-helper -d /dev/sda

...where /dev/sda is the external USB you wish to use for a root filesystem.

Sources and Further Reading

This script is mostly an implementation of the process outlined in paulv's HOWTO: Move the filesystem to a USB stick on the Raspberry Pi forums, with additional help from the following sources:

The Arch Linux wiki, GUID Partition Table for what a GPT is and some parted commands.
GUID Partition Table, Wikipedia
Booting from an external USB drive, from the Raspberry Pi StackExchange.
Booting a Raspberry Pi reliably from USB in the presence of multiple USB drives, by Stefan Krastanov.
Speed up your Pi by booting to a USB flash drive, by Sam Hobbs.
This comment on root= in init/do_mounts.c in the Linux source tree.

Along with manual / info pages for: