Server configuration
At first you have to install XDebug (out of scope of this article).On the vagrant machine we need kind of this configuration in /etc/php.ini
[xdebug] zend_extension=/home/www/PHP/php-5.5.22/lib/php/extensions/xdebug.so xdebug.max_nesting_level=9999 xdebug.profiler_output_dir=/tmp/ xdebug.profiler_output_name=xdebug-%p xdebug.profiler_append=1 xdebug.profiler_enable_trigger=1 xdebug.remote_enable=1 xdebug.remote_handler=dbgp xdebug.remote_mode=req xdebug.remote_host=10.0.25.21 ;xdebug.remote_connect_back=1 xdebug.remote_port=9000 xdebug.idekey="PHPSTORM" xdebug.remote_autostart=1 xdebug.profiler_enable=0 xdebug.trace_options=1
Restart apache or php processes (depending on your server setup).
Important settings are: remote_host, idekey, remote_enable, remote_autostart