I see, that makes sense. Thanks. I would also like to avoid it if possible. But in order to avoid it, I have to find out why this is happening:
As you can probably see, syslog-ng writes every minute at least. I guess that's because my user crontab has a command that gets run every minute. What I don't get is why syslog-ng writes to the disk, even though I'm telling it not to log crond's output.
Any ideas? As you can see from my syslog-ng.conf, everything that has to do with crond is sent to /dev/null. So crond output shouldn't cause a spin-up of my harddrive, but it does. Killing crond or removing the once-per-minute-command from my user crontab will allow my harddrive to stay spinned down for a long period of time. But I would rather not do either.