Akonadi

Introduction

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, 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.

KMail
	Mail Client Uses Akonadi to store emails
KAddressBook
	Contact Manager Uses Akonadi to store contact information
KOrganizer
	Personal Organizer Uses Akonadi to store calendars, events, journals, etc.
KJots
	Note Taking Application Uses Akonadi to store notes
KAlarm
	Personal alarm scheduler Uses Akonadi to store alarms

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 in System Settings 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.

To start the Akonadi server,

akonadictl start

To stop the Akonadi server,

akonadictl stop

To restart a running Akonadi server,

akonadictl restart

To query the status of the Akonadi server,

akonadictl status

Disabling the Akonadi subsystem

Remember

If you don't want to have Akonadi running on your system, you can not use any of the Akonadi-enabled applications. Such applications will start Akonadi, whenever they need its services even if you have disabled it. See the list of Akonadi-enabled applications. Also note, that some Plasma widgets, such as the Digital Clock uses Akonadi

The Akonadi server is launched automatically at login whenever any Akonadi-enabled application requests access to it.

To disable the Akonadi subsystem, first, shut down the running Akonadi server from the control module or the command line:

akonadictl stop

Now, edit the file ~/.config/akonadi/akonadiserverrc and change StartServer from true to false:

StartServer=false

The Akonadi server should no longer launch automatically on login.

Note

The Akonadi server will still be started by any Akonadi-enabled application. 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. You must remove any widgets that may start it from your start-up, if you wish Akonadi to remain disabled.

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

Migration problems

Akonadi's Glossary entry has a brief description of its purpose and other useful links. This page explains how Akonadi and KAddressBook work together.

High CPU or Memory usage

If you are experiencing 100% CPU usage by the virtuoso-t process when using Akonadi and related applications, try this proposed workaround while it is being investigated: In KRunner's configuration page, disable the Nepomuk search plugin and the Contact plugin. Then, log out and back in. For further information and inputs, report back here or on the Forum or on the IRC channel #kontact.

Akonadi and Nepomuk, why?

There is often a good deal of confusion about Akonadi and Nepomuk. Why data from Akonadi is indexed in Nepomuk explains exactly why we have both, and what their roles are. Don't miss the additional information from Will Stephenson in the Comments section.