Does anybody really know for sure just what/when triggers an fsck?

I had a look through the source code. The defaults are every 20 mounts or every 6 months. I guess only read/write mounts increment the counter, so this effectively means every 20 synchs rather than every 20 reboots. Obviously, the defaults can be changed, but I doubt empeg have done that if they haven't spoken up by now.

Borislav