Posts: 103
Joined: Sat Jul 19, 2014 9:43 pm

Raspberry Pi 3b+ boot from USB SATA SSD

Thu Jul 18, 2019 7:37 am

Hi guys,
Quite some time ago I set up on of my Raspberry Pis (mobel 3b+) at my work to automate various tasks. To increase reliability, I decided to use a Kingston SSD I had lying around to boot and run from instead of the MicroSD card. I used one of the USB3.0 SATA adaptors bought from Pimoroni (product code ADP001). This has been, and still is working fine with the data USB plugged into the Pi and the power USB cable plugged into a 5V 2.0A USB plug from an old mobile phone. However, since I bought a Raspberry PI 4 I noticed that the Pi could power the SSD (or a 2.5" HDD) all by itself rather than using a separate USB power supply for the second cable of the adaptor to help power the drive (not for booting too, just as an extra drive). So, I tried using the same adaptor on an older Raspberry Pi 2 that I use as a media server, and it manages to power an old 2.5" laptop HDD that I also had lying around without the use of an extra power supply (both USB cables plugging to the Pi).

Now for my problem (apologies for the long story above!)…

If I try to power the boot SSD in my Raspberry Pi 3b+ without an extra power supply for the SSD (both USB cables plugged into the Pi), it does not boot. If I use an extra power supply and switch it on before switching on the Pi power, it does boot. I have tried adding the following entry to my /boot/config.txt file:

Code: Select all

# New entry to try to boot to SSD without extra power
But it made no difference. Is there something else I need to do to allow the SSD to power up before it boots? I'm presuming that the SSD is not being powered up early enough for the Pi to read it to boot from...

Posts: 4184
Joined: Sat Jun 16, 2018 12:49 am
Location: Lincs U.K.

Re: Raspberry Pi 3b+ boot from USB SATA SSD

Thu Jul 18, 2019 1:54 pm

Strange - I would have thought the SSD would be their before the Pi :?:

You could move the /boot to a SD card and add

Code: Select all

to the cmdline.txt file

Adding anything into config.txt on the SSD will not help the Pi finding the disk as it needs to find the disk to read it first!

Also try swapping cables with a normal one - unless you have other things plugged in an official power supply should cope with the drive. You do have the official power supplier don't you?
Need Pi spray - these things are breeding in my house...

Return to “Troubleshooting”