Because Parallels Desktop 10 and Fusion 7 both run slow on Yosemite, there are KB articles which make the users execute
sudo nvram boot-args="debug=0x10"
For instance here: http://kb.parallels.com/122767
I have figured out that 0x10 will "make ddb the default debugger". But I have no idea what this means, yet it sounds scary.
What will this command do to Yosemite/the Mac? Can it have any other side effects?