C. Booting from USB

Booting from a USB HDD, USB SSD or Flash Drive

Because we are using a microSD card to store the OS we do not take advantage of the full benefits of using a Linux distro, being lightweight i'm naturally referring to speed.

Depending on the card we're using we can have speeds from 25 MBps to 50 MBps (theoretically, but the best cards usually go up to 38 MBps).

Again depending on whether we're using a flash drive, or HDD or SDD we can go up to I/O 140MBps / 200 MBps

Keep in mind that we already have Ubuntu installed on the memory card. I think we can also directly on an USB Storage Drive but for that we would need to start the process from scratch going back to the imager (more details here ).

PREREQUISITES Raspbian OS - the only stable way to boot from USB is to have an micro SD card with the original operating system installed and an USB device with Ubuntu installed.

[Side story] Install rpi-eeprom

rpi-eeprom - is a library that we will use to clone our card onto the USB drive

1. Boot from your standard microSD card

2. Update your OS and firmware (if done recently, you can skip this step)

    $sudo apt update
    $sudo apt full-upgrade
    $sudo rpi-update

3. Reboot the Raspberry Pi

    $sudo reboot

4. Install the latest bootloader

    $sudo rpi-eeprom-update -d -a

5. Reboot the raspberry again

6. Launch raspi-config

    $sudo rpi-eeprom-update -d -a

7. Select Boot Options (3) (then press Enter)

8. Select Boot ROM Version (then Enter)

9. Select Latest and then OK

10. Select No to use latest boot ROM, then press OK

11. Select Boot Order and press Enter

12. Select USB Boot, then choose OK

13. Select Finish, but do not reboot (select No)

14. If you do not have Ubuntu already installed on the USB drive -> Launch SD Card Copier (the usb device should be connected to the raspberry using USB 3 port)

15. Select the Copy from Device (micro SD card) and the Copy to Device (flash drive, HDD or SDD). Click Start, the process should take about 10m.

16. Shut down the Raspberry

    $sudo shutdown -h

17. Remove the microSD card

18. Power up and it will boot from USB