When the kernel cannot continue executing for some reason, it "panics," and part of the panic-message is a note of whether the panic occurred while the kernel was doing a write to the filesystem. (Nearly always it is not, fortunately, so that part of the message is: "not syncing.")
The last part of the message is the "real" message. In this case, one of the required system processes ... which are not permitted ever to terminate ... ran into a situation where they cannot continue to execute. And so, if they can't keep going, neither can the system itself.
This message is usually "the final paws-up gasp" of the system, and messages preceding it are the true cause of the problem.
Last edited by sundialsvcs; 04-15-2012 at 10:29 PM.