CPU usage and disk activity

[Stefan Froehlich]

I recently installed Kolab 3.0 on a Debian Wheezy box. Today at about 
4pm it started with some disk activity and high cpu load. As soon as I 
stop the kolab-server there is no disk activity and cpu load is normal. 
Starting kolab-server again restarts disk activity and cpu load as well. 
Now it is 9pm and the disk activity and cpu load is still above normal.
As far as i can see there is nothing suspicious in the logs. What causes 
the disk activity?

MfG Stefan Fröhlich
42 ;-)