Paul, > my guess is that the DB crashed so the 'tc.log' file was created and it > prevent the mariadb-server to start again. After a discussion with Elena Stepanova, here is some information on the 'tc.log' file: [...] tc.log wouldn't prevent mariadb from starting, it's there to help, not to obstruct. It's more likely that the tc.log is invalid on whatever reason (e.g. got corrupt due to a disk problem or lack of space, or as a result of a bug in the previous installation, or is of an incompatible format). You can very easily get the same effect if you stop the server, run touch <datadir>/tc.log (assuming you don't have one) and then try to start the server.
Documentation on how this 'tc.log' file work is quite inexistent because: [...] it has never been meaningfully documented, neither in MariaDB nor in MySQL. Hopefully it will change soon [...]. There is a documentation request filed on https://jira.mariadb.org/browse/MDEV-16442 So regarding our issue, I guess that the DB crashed or the tc.log file got corrupt (or both). Do you know how to reproduce this? Do you have any steps that I could try? -- Faustin Lammler MariaDB Foundation