Comment 3 for bug 1093870

Usually the wd_keepalive daemon would be started early for this reason, to keep the hardware from timing out. Once the machine is up it would hand over to the watchdog daemon that runs system tests.

I am guessing that the at-boot fsck is run before loading anything (daemons, etc) so all the file systems are free of any open handles, etc, that might cause problems for repair actions. I'm not sure how easy it would be to get round that problem.