Just in case there are any new Mastodon instance admins out there reading this, the number one thing you need to have in place if you want any sustained presence on the open web is a backup system in place and tested. This was one of the things I found early on with the !Freedombone project. If you don't have backups, or only an untested system, then any database corruption, failed hard drive or whatever can delete your entire user community overnight. I think that happened to at least one gnusocial server after the 2016 Twitter exodus.

Freedombone uses Obnam to do encrypted backups with a gpg key, but there are various other options available.