Comment 3 for bug 97645

Linux kernel flushes all disk caches before going down. All the halt/poweroff/reboot call sync before proceeding. You can even see a message about it flashing extremely fast right before the reboot/whatever initiates. Only thing that you can add is forcing remount as read-only. That happens with Ubuntu as well. These measures already do pretty much everything that is possible, and at least I can't see anything else that would be doable.

I would instead of that focus on fixing the misbehaving applications. (daemontools?)