Booting off a USB

In openSUSE Tumbleweed, how do you boot off a USB drive?

It isn’t really a Tumbleweed question, because it happens before you have Tumbleweed booted.

Mostly, it is up to your BIOS or UEFI firmware.

On all of my systems, I hit F12 while booting, and that gives me a BIOS boot menu. And I select the boot device in that menu.

Others systems may use different keys – I think it is F9 for HP computers. But F12 is fairly common.

You didn’t mention the hardware system you’re using. I can’t provide guidance about USB booting on other hardware, but if you’re using a Raspberry Pi-3/3+ (won’t work at all on earlier versions), there’s a one-time process you need to do, in Raspbian, as described here:

After this one-time process, just insert your USB medium with Raspberry Pi-3 Tumbleweed on it (new install or running system) in a Pi-3/3+ USB port and power up.