This is the central part of your dpkg output: Preparing to unpack .../mariadb-server-core-5.5_5.5.37-0ubuntu0.14.04.1_amd64.deb ... Unpacking mariadb-server-core-5.5 (5.5.37-0ubuntu0.14.04.1) ... Selecting previously unselected package mariadb-server-5.5. Preparing to unpack .../mariadb-server-5.5_5.5.37-0ubuntu0.14.04.1_amd64.deb ... Aborting downgrade from (at least) 5.6 to 5.5. If are sure you want to downgrade to 5.5, remove the file /var/lib/mysql/debian-*.flag and try installing again. dpkg: error processing archive /var/cache/apt/archives/mariadb-server-5.5_5.5.37-0ubuntu0.14.04.1_amd64.deb (--unpack): subprocess new pre-installation script returned error exit status 1 Selecting previously unselected package mariadb-server. Preparing to unpack .../mariadb-server_5.5.37-0ubuntu0.14.04.1_all.deb ... Unpacking mariadb-server (5.5.37-0ubuntu0.14.04.1) ... Processing triggers for man-db (2.6.6-1) ... Errors were encountered while processing: /var/cache/apt/archives/mariadb-server-5.5_5.5.37-0ubuntu0.14.04.1_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1)
Note the lines: Aborting downgrade from (at least) 5.6 to 5.5. If are sure you want to downgrade to 5.5, remove the file /var/lib/mysql/debian-*.flag and try installing again. This is by design - the packaging of all MySQL and MariaDB versions 5.1, 5.2, 5.3 etc have this hook built-it that will stop people for downgrading. The MySQL/MariaDB data files are not promised to be backwards compatible, thus running a 5.5 version on 5.6 data might lead to corruption. Safest way is for you run mysqldump to get your data in pure SQL format, then remove MySQL 5.6 and install MariaDB. ** Changed in: mariadb-5.5 (Ubuntu) Status: New => Opinion ** Summary changed: - Unable to install package mariadb-server-5.5 if mysql-server-5.6 was installed on Ubuntu 14.04 + Unable to downgrade automatically to mariadb-server-5.5 if mysql-server-5.6 was installed on Ubuntu 14.04 ** Summary changed: - Unable to downgrade automatically to mariadb-server-5.5 if mysql-server-5.6 was installed on Ubuntu 14.04 + Unable to downgrade fully automatically to mariadb-server-5.5 if mysql-server-5.6 was installed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1330496 Title: Unable to downgrade fully automatically to mariadb-server-5.5 if mysql-server-5.6 was installed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mariadb-5.5/+bug/1330496/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs