Next hurdle

Maybe you have one of the old Raspberry 4 models?

"What about older Raspberry PI models?

This article primarily focuses on booting a Raspberry PI 4, 400 and Compute Module 4 from a USB drive. However, with a little trick, you can reap the same benefits if you own an older model such as a Raspberry PI 1, 2, 3 or Zero. The trick involves moving the root file system (/) to a USB drive and just leave the boot file system (\boot) on the SD card.

With this approach, your Raspberry PI still boots from the SD card. However, the actual operating system itself runs from the USB drive. Since the boot operation only needs to reads from the SD card, you won’t run into SD card corruption problems. Just keep in mind that you get better disk I/O performance on a Raspberry PI 4, because it supports USB 3 ports. For step-by-step instructions on using this approach, refer to this tutorial:

Move the Raspberry PI root file system to a USB drive

What do you need

To complete the steps outlined in this tutorial, you need the following:

A basic Raspberry PI 4 setup. This includes a power supply, SD card, HDMI cable, monitor, mouse and keyboard. The Raspberry PI Imager software installed on your PC. A USB drive.

Theoretically you can use a simple 4 GB or more USB flash stick for this tutorial. However, for the best performance I recommend a SATA or NVMe SSD drive with a suitable USB 3 adapter. For this tutorial, I’ll use a Samsung 860 EVO 250 GB SSD in combination with a Nedis USB 3.2

Fix for getting your SSD working via USB 3 on your Raspberry PI..."

Nope. Brand new 4B. I stumbled through the mirk, somewhat hampered by the fact that I interpreted the flashing green light as being some kind of malfunction, whereas I eventually discovered it was simply looking for an SD card that wasn't there, but still eventually booted.

The key was to relabel the root FS and use that in fstab and in cmdline.txt And tell the green light to shut the f up. Then I finally got a clean boot and was able to expand the root FS to the whole SSD.

The next issue is to find some 2TB SSDs that don't flatten the USB power supply.

It looks like cheaper and slower is less power...

Probably not relevant but I've just spent the best part of an afternoon trying to get a 2Gb Pi4 to boot from an SSD via a USB3 (allegedly) to SSD adaptor.

To save time I decided to use Raspberry Pi Imager (on a Mint desktop) to burn the image. It didn't work (write failure). I moved the SSD adaptor to a USB-2 port and it worked.

If I plug the resulting combination into a USB-3 slot on the Pi 4 it boots perfectly.

I think the adaptor works on the Pi USB-3 because the Pi 4 doesn't have true USB-3 data rates. I haven't got a Pi 5 but I suspect the same approach will not work.

Another Dave

All SATA /SSD adapters are not created equal

Allegedly.

What does lsusb show about the adapter?

PS Id I had known that a Pi4B would boot USB *by default* (if no SD card is installed) I wouldn't have faffed around with the SD card..

The symptoms you describe would also fit perfectly with a power supply issue. Because of power limiting at USB ports, voltages at the USB devices can be marginal. This shows up most often with relatively high consumers of power, like storage drives.

David

That depends on the PC driving it. As far as a PI is concerned they have up to 6W of USB power available which is enough for the hungriest SSD, two reasonably abstemious ones and possible a third if small enough.

We shall see.

VIA Labs, Inc, VL711 SATA 6 Gb/s bridge

I did know (but had forgotten) this as I had sorted it out when the Pi 4 first came out. It was only when I got into the mire of PARTUUID and the rest that it dawned on me I was wasting my time and should bypass all attempts to use the live OS to copy the system to the SSD.

Another Dave