Well, since things were already falling apart at the seams after my aborted upgrade, I decided to finish the job. As it turns out, it would seem the init scripts my hosting provider uses weren't quite killing tomcat. killall -9 took care of the zombie processes and the upgrade went mostly smooth after that. So at least I'm up and running now. I think I'll see to dinner with my wife and daughter. Enough for one day. (I hope.)