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Looking into the error: "ERROR: Database files are locked. Daemon already running?" and the statement in mysql's error.log "[InnoDB] Unable to lock ./ibdata1 error: 11" it seems like another instance of mysql was locking the files. Do you know if any separate instances of mysql were running at that time? Alternatively, this may have been caused by uninstalling and reinstalling mysql. In the dpkg history it shows the following commands: apt-get install -y mysql-server apt upgrade apt-get remove --purge mysql* -y apt-get autoremove -y apt-get install -y mysql-server The previous install may have blocked the second one from completing. Was there a specific reason for uninstalling and reinstalling? Did any errors show up during the first install? Thanks ** Changed in: mysql-8.0 (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1960971 Title: package mysql-server-8.0 8.0.28-0ubuntu0.20.04.3 failed to install/upgrade: installed mysql-server-8.0 package post-installation script subprocess returned error exit status 1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mysql-8.0/+bug/1960971/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs