[solved] MariaDB 10.1 to MariaDB 10.2 upgrade crash

Here is an experience report fix for the record -

Even after being removed and re-installed Mariadb still refused to start.

/var/lib/mysql/mysql-error.log noted this problem

2018-03-21 5:51:01 140370956769472 [ERROR] InnoDB: Upgrade after a crash is not supported. This redo log was created before MariaDB 10.2.2, and we did not find a valid checkpoint. Please follow the instructions at Upgrading MariaDB - MariaDB Knowledge Base
2018-03-21 5:51:01 140370956769472 [ERROR] InnoDB: Plugin initialization aborted with error Generic error
2018-03-21 5:51:02 140370956769472 [Note] InnoDB: Starting shutdown…
2018-03-21 5:51:02 140370956769472 [ERROR] Plugin ‘InnoDB’ init function returned error.
2018-03-21 5:51:02 140370956769472 [ERROR] Plugin ‘InnoDB’ registration as a STORAGE ENGINE failed.

This noted the fix https://mariadb.com/kb/en/library/upgrading-from-mariadb-101-to-mariadb-102/+comments/2903

That is, to remove these /var/lib/mysql/ib_logfile* that prevented the upgrade to startup.


Note the response to the question on the MariaDB KB article.

You need to go back to your previous version and shutdown cleanly (not a crash) before installing a MariaDB-10.2+ version.

Deleting ib_logfile* can result in dataloss and unrecoverable data directory. From 10.8+, MariaDB won’t start without an ib_logfile0 existing.