Drush site-upgrade : "Unknown option: --uninstall"
My Drush configuration file was simply misplaced, I had to put it in Drupal's directory (sites/all/drush/drushrc.php) rather than ~/.drush/

When running drush status from your Drupal source site directory, make sure there is a Drush configuration loaded.

Drush version                   :  6.2.0
Drush configuration             :  /var/www/html/drupal/sites/all/drush/drushrc.php
Drush alias files               :  /root/.drush/my.alias.drushrc.php


And here is the content of file sites/all/drush/drushrc.php

&lt;?php
$options['strict'] = FALSE;