Thank you for taking the time to file a bug report. Per your console log:
Renaming removed key_buffer and myisam-recover options (if present) Initialization of mysqld failed: 0 Warning: Unable to start the server. Please restart MySQL and run mysql_upgrade to ensure the database is ready for use. /var/lib/mysql/ibdata1: 30680 ERROR: Database files are locked. Daemon already running? Warning: Unable to start the server. Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details. invoke-rc.d: initscript mysql, action "start" failed. It looks that previous database process (the existing/installed one) hasn't shutdown correctly and it is still holding a lock for the database file. Make sure you kill existing previous databases processes and try again re-starting the mysql service. Since it seems likely to me that this is a local configuration problem, rather than a bug in Ubuntu, I am marking this bug as 'Incomplete'. However, if you believe that this is really a bug in Ubuntu, then we would be grateful if you would provide a more complete description of the problem with steps to reproduce, explain why you believe this is a bug in Ubuntu rather than a problem specific to your system, and then change the bug status back to "New". For local configuration issues, you can find assistance here: http://www.ubuntu.com/support/community ** Changed in: mysql-5.7 (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Server, which is subscribed to mysql-5.7 in Ubuntu. Matching subscriptions: main https://bugs.launchpad.net/bugs/1879155 Title: package mysql-server-5.7 5.7.21-1ubuntu1 failed to install/upgrade: installed mysql-server-5.7 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-5.7/+bug/1879155/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
