Technology Insights

mysql-server debconf Variables

The purpose of this article is to list the variables that are available to set when installing mysql-server on Ubuntu Linux. You can use the debconf-get-selections command to list debconf variables for any installed package on Ubuntu but the debconf variables are most useful before a package is installed so I constantly find myself having to login to another Ubuntu server where the package is already installed to get these variables. Now I can just look on QD.

Technology Insights

Flush debconf Database On Ubuntu Linux

If you have used the debconf-set-selections command that I mentioned in a previous article there will likely be more questions that come up over time such as how to view variables that have been set for specific packages or how to flush the debconf database. Below I show a couple example that explain how to view variables in the debconf database and also how to remove those variables from the database.

Technology Insights

Install MySQL Automatically On Ubuntu

If you need to complete an unattended installation or scripted install of MySQL On Ubuntu Linux you can do so easily by setting the necessary variable with debconf-set-selections. Typically when you install MySQL on Ubuntu it will pop up a window and ask for you to enter a password even when you have specified -y with apt-get install. Below are the commands necessary to set the password variable which then allow you to automatically install MySQL on Ubuntu.

Technology Errors

ERROR 1146 (42S02): Table ‘mysql.servers’ doesn’t exist

Earlier today while adding a new site to a server running as a web server with many virtual hosts I ran into an error flushing the privileges after I added a new MySQL database followed by a user with only access to that new MySQL database. After a bit of investigation I realized that when I recently updated the MySQL server on the CentOS Linux server in question it must have had some issues during the upgrade. Below I describe not only the error in more detail but also how to resolve the MySQL error when attempting to flush the privileges.