The Akonadi framework is responsible for providing applications with a centralized database to store, index and retrieve the user's personal information. This includes the user's emails, contacts, calendars, events, journals, alarms, notes, etc. In SC 4.4, KAddressBook became the first application to start using the Akonadi framework. In SC 4.7, KMail, KOrganizer, KJots, etc. were updated to use Akonadi as well. In addition, several Plasma widgets also use Akonadi to store and retrieve calendar events, notes, etc.
At the time of writing (August, 2011), the following applications are enabled to use the Akonadi framework to centrally store and access user data. Follow through to each application's page to learn more.
Uses Akonadi to store emails
Uses Akonadi to store contact information
Uses Akonadi to store calendars, events, journals, etc.
Note Taking Application
Uses Akonadi to store notes
In addition to this, plasma widgets like the Digital Clock widget, the Notes widget also use Akonadi to store and retrieve events and notes.
Controlling the Akonadi server
The Akonadi control module started by the context menu of the Akonadi tray icon provides an easy means to starting, stopping, restarting and querying the status of the Akonadi server. You may also accomplish this from the commandline using the command
akonadictl. Using this method, you can get additional useful information on the console.
To start the Akonadi server,
To stop the Akonadi server,
To restart a running Akonadi server,
To query the status of the Akonadi server,
Disabling the Akonadi subsystem
The Akonadi server is started by any Akonadi-enabled application. If you don't want Akonadi to be started after login, you have to ensure that no Akonadi-enabled application is launched at login or thereafter. Remember to check Plasma widgets as well — the Digital Clock widget in the default panel, for instance uses Akonadi to (optionally) display calendar events and this is enabled in its settings by default (see the "Display Events" option) . You must remove any widgets that may start it from your start-up, if you wish Akonadi to start only when you start KMail or other applications.
The Akonadi server is launched automatically at login whenever any Akonadi-enabled application requests access to it.
To disable the Akonadi subsystem, shut down the running Akonadi server from the control module or the command line:
To ensure that Akonadi is not started, check that no applications require it at login. In particular, open the Plasma clock applet preferences, go toand uncheck to prevent Plasma from requesting information from Akonadi and thus allowing it to start.
Frequently Asked Questions
Where is my data now?
A full explanation of where the data is stored and Akonadi's interaction with it is available in Andras Mantia's blog
How to upgrade my PostgreSQL database?
After updating your PostgreSQL server to a new major version, sometimes you will have to convert your Akonadi database for use with this new version. Instructions can be found on this page.
Akonadi's Glossary entry has a brief description of Akonadi's purpose, and other useful links. This page explains how Akonadi and KAddressBook work together.