I have a teamcity install (9.0.3 (build 32334)) that I did a year or so ago (I think) that I've been looking into upgrading to the latest version. When I went to do a backup from the Web UI I get an error:
UnexpectedDBException: Unexpected exception MySQLSyntaxErrorException: SQL error when doing: Executing a SQL statement SQL query: truncate table backup_builds SQL exception: Table 'teamcity.backup_builds' doesn't exist
caused by MySQLSyntaxErrorException: Table 'teamcity.backup_builds' doesn't exist
After seeing this I logged into my mysql instance with the teamcity credentials and checked the database. It shows no tables, at all. When I look in the global settings it claims it's using mysql and the connection settings all look correct in the database.properties file.
Everything else works fine. It builds the two projects I've got set up, it seems to keep the build history and everything so I'm not sure where it's storing that data but it definitely doesn't seem to be in mysql like it thinks.