Sorry for the delay ...
No, the newnode MFS is special. When the node is in that, you
cannot reboot from the web interface.
I'm confused. When, at the end of the node creation process the web
interface says "rebooting node w.x.y.z" is it trying to run "wap
newnode_reboot w.x.y.z"?
Yes.
Or is it just lying and, for this one special case, you've got to go
physically reboot the machine to get it to boot the admin mfs for
the first time?
No, you do not have to do this! Something is not configured properly
if this fails.
For what it's worth I tried a "wap newnode_reboot w.x.y.z" for a
node in freebsd.newnode whose address was w.x.y.z and it didn't
reboot. Is that a problem and, if so, is it worth debugging?
Yes, this is a problem since it indicates possibly wider problem.
So, did newnode_reboot say anything interesting or did it just sit
there? One thing you can try is:
boss> sudo ssh -v -l root -i /usr/testbed/etc/identity.newnode w.x.y.z
and see if it says anything that might help.