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It looks like you have tried a number of things to resolve this problem; however I think that the original cause of the issue may have been that the InnoDB file locations in /etc/mysql/my.cnf where outside of the apparmor profile and hence rw access to them was denied. If possible I think that its worth trying to purge the packages and re- install using the following commands: sudo apt-get purge mysql-server-5.1 sudo apt-get install mysql-server-5.1 This should ensure that you have an up-to-date base apparmor configuration. /etc/mysql/my.cnf is installed by mysql-common so this should leave your configuration intact - however this does mean that mysql will fail to start during the setup phase of the install. You will then need to update the apparmor profile in /etc/apparmor.d/usr.sbin.mysql to include rw access to this location; I think you will be able to complete the installation by running the following command: sudo dpkg-reconfigure mysql-server-5.1 Please update this bug report if this resolves your issue. ** Changed in: mysql-dfsg-5.1 (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to mysql-dfsg-5.1 in ubuntu. https://bugs.launchpad.net/bugs/735830 Title: package mysql-server-5.1 5.1.37-1ubuntu5.5 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1 -- 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