I just updated also...why do you want to disable? Don't know how off hand but wondering if there is some issue with the update???
These commands worked up through Low Sierra.
Not sure if they still work in High Sierra.
STOP Spotlight indexing:
sudo mdutil -a -i off
REMOVE the Spotlight index:
sudo rm -rf /.Spotlight-V100/*
Just out of curiosity. Is there some reason to disable Spotlight? Are there privacy concerns?
That is why I want to know If I can disable Spotlight
Camelia