I happened to find [1] where some resolved it by disabling/enabling services. But for your case that isn't sufficient, it seems to be "files leftover" and "partial upgrade due to the former breaking the services"
[1]: https://askubuntu.com/questions/1235829/cant-get-mysql8-to-work-on- ubuntu-20-04 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1962369 Title: mysql install fails - Unknown redo log format (103) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mysql-8.0/+bug/1962369/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
