Just paste in a chunk of systemd (or whatever) logs and start asking questions. Often just pasting in the logs and pressing enter results in it identifying potential problems and suggesting solutions. It helped me troubleshoot a huge amount of issues on linux desktops and servers that would have taken me a lot longer with google - even if it doesn't always give the right solution, 99% of the time it at least points to the source of the error and gives me searchable keywords.
Note it works much better with GPT4 - gpt3.5 tends to hallucinate a bit too often.
I highly recommend considering GPT-4 every time you encounter a painful manual process. In nearly every case where I have applied GPT-4, it has been successful in one-shot or few-shot solving the problem.