Where is Drush installed?
We needed to create some site aliases for our system during upgrading sites from Drupal 6 up to Drupal 7. This Drupal development service can be tricky but greatly helped by Domain aliases.
Anyway the command to find the installation of Drush on your system is:
drush site-alias @self --full --with-optional
This needs to be run from within your Drupal directory.