That is unfortunately beyond my knowledge. I’ve never read up on settimg up an instance so I’m not sure. From the user side, I don’t think most people mirror their instances, since most are volunteers renting space somewhere or running a small home instance for themselves or a small group.

I have seen the owner of an instance announce that they were shutting down in three months and to find a new home on a couple of occasions. Not quite the same, but a similar impermanence.