Is there a guide to Upgrading a FreeBSD server remotely

[Denis Fortin]

Greetings,

I've Google'd a bit, but I cannot find a "survival guide to upgrading 
a FreeBSD system remotely".

The Handbook's procedure is excellent (cvsup to the RELENG branch and 
then make'ing world), but it requires going into single user mode and 
using the console, two things which may not be possible in the context 
of a server sitting unattended in a hosting center 10000 kilometers away.

Has anyone written a quick guide on issues that can arise in this kind 
of situation?  (For instance, one the the issues is that one might end 
up with a bad kernel: have people devised a way for the boot code to 
interact with "reboot -k xxx" to revert to the default kernel after an 
unsucessful boot, or after a specific time?)

Thanks

Denis Fortin, fortin at acm.org