Reducing the memory footprint of Akonadi

I have some systems where I don’t use Kontact or anything else that makes use of Akonadi, so my Akonadi database is empty. Still I find the Akonadi server and its numerous agents running when I have just started my session.

The Akonadi server is only started when some application needs it. So who wants to communicate with Akonadi? After some search, I found that the clock applet on the Plasma panel is the culprit. It has a feature to display events from the Akonadi calendar which is enabled by default (and I don’t want to oppose this choice; it’s a very nice integration feature for people using KOrganizer).

So if you want to prevent the Akonadi server from starting on systems where you don’t use Akonadi, or just want to speed up the startup of your KDE session by delaying Akonadi’s startup until it’s actually needed, do the following: Go to the configuration of the clock applet, and disable “Display Events” in the “Calendar” section.

To check whether Akonadi is running, open the “System Activity” monitor with Ctrl+Esc (or by clicking on the second icon from the left in KRunner). Look for a process called “akonadiserver”. (There will also be multiple processes with names like “akonadi_agent_launcher” or “akonadi_whatever_resource”.) You can also manually start and stop Akonadi with the commands “akonadictl start” and “akonadictl stop” (from either the command line or KRunner).