I fall back to !g when I don't find what I'm looking for. It happens too often for technical things. And Google is the only one that handles "verbatim searches". At least I'm splitting my trail of data between two companies.
I looked on DDG for _ubuntu turn on a usb disk after it was switched off_ and it didn't return anything related to the query. I added !g and Google gave me [1] as the second result.
It’s common for “ambiguous search terms” similar to “python database”.
I’d bet that an experienced ddg user might have workarounds for this kind of thing. I’ve certainly found adding a few extra terms gives me what I need.