“restricted” folder/files in OS X El Capitan

Question

After upgrading from OS X Yosemite to OS X El Capitan Developer Preview, I tried to edit /System/Library/LaunchDaemons/ssh.plist to change the default SSH

Answer 1

I would suggest you try adding whatever arguments you need to a plist in /Library/Preferences/. For example, in my case I needed to make a slight alteration to mDNSResponder to add the AlwaysAppendSearchDomains flag. As suggested by "bwells" on the Apple developer forums, I just had to do

sudo launchctl unload /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist
sudo defaults write /Library/Preferences/com.apple.mDNSResponder.plist AlwaysAppendSearchDomains -bool YES
sudo launchctl load /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

This is a much cleaner approach and persists across reboots and should also survive an upgrade (at least during the betas my manual changes after disabling SIP were overwritten). Note, as far as I know this is new to El Capitan.