Raspberry Pi 4 Boot with USB

Raspberry Pi single board computers have historically booted from microSD flash cards. This works OK, but isn’t nearly as solid a solution as an SSD or M.2 hard drive. 

Earlier in 2020, Raspberry Pi 4 gained the ability to boot from USB which means any hard drive that can be connected to the Pi via USB (typically USB 3.0) and recognized by the OS can be used as a boot device. Most common external boot devices are SSD hard drives and M.2 hard drives – but you could even use something like a USB flash drive.

The problem with booting a Raspberry Pi to an external USB hard drive is that there isn’t much documentation on how to do this properly – when Raspberry Pi’s first gained this capability, it required manual upgrades to Beta bootloaders, and some configuration changes to make it work. This has since changed, and it’s much easier with newer versions of Raspbian – but of course all of that old documentation still exists on the web and can be extremely confusing for anyone searching for how to accomplish USB boot.

So in this tutorial, we’re going to show you how to get a Raspberry Pi to boot from USB as of December 2020 and early 2021.