How to test rc.local file

Simulate the run

sudo /etc/init.d/rc.local start

Debug the real execution after startup

Add this code to the begining of your /etc/rc.local file:

# stdout redirect
exec 2> /tmp/rc.local.log      # send stderr from rc.local to a log file
exec 1>&2                      # send stdout to the same log file
set -x                         # tell sh to display commands before execution