I have a RB PI4 8Gb model, and I am using it as a home server, running Ubuntu Server 20.10 I did all steps properly to boot the OS from the USB properly ( https://www.google.com/amp/s/www.tomshardware.com/amp/how-to/boot-raspberry-pi-4-usb) , to use a SSD. Sometimes it does it, but sometimes it gets stuck at the "Bios" image, so after rebooting it many times it boots properly again. How can I make it 100% times boot from USB?

My gear: Case with ssd reader built-in: ARGON ONE M2 case SSD: Western Digital M2 sata 500gb Official Raspberry Pi power supply.

  • what brand and model is the USB to SSD adapter? even the PID:VID of the device will be useful info Mar 9, 2021 at 23:48

3 Answers 3


If this happens before the kernel has a chance to run, the most likely cause is insufficient or unstable power supply, which makes a USB device sporadically undetectable at boot.

If the kernel has a chance to run, you could try to enable earlycon to collect early boot messages via UART.


Not sure if this is the case for you but are you sure it is failing to boot? I have a rp4 8gb setup with berry boot and it boots to a 5tb USB hard drive that is connected to a USB hub and I can say for sure that sometimes it takes a very long time for it to find the drive to boot from. My boot usb detection can take almost a full minute before it finds the drive. but so fare it has never failed to boot. As for the power problem that very will can be your problem if it is totally failing to boot. I have mine plugged into a powered usb hub so I do not have power issues. Yes it looks kinda crazy the why I have it but it does work.


I had similar problem and the issue was the power: I added a cable with the switch (from pihut.com) and it caused it. Once I removed this piece of hardware issue never happened again.

  • 1
    I am using the official Raspberry power cable. The ssd is a M2 sata, so it should not requier that much power.
    – Nassif 113
    Mar 9, 2021 at 19:02
  • check the connection quality inside Argon - I am using Argon M2 cases (2) with M2 SSD - my observation: Argon One case brings sometimes issues with voltage dropping on contacts - the easiest way to eliminate would be: 1- take the raspberry out of Argon, 2- connect the power cable directly to raspberry 3-connect ssd to USB 4- turn on the power - if in such scenario all is ok then you know - inside Argon connection is the issue Mar 10, 2021 at 13:26

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