3 Golden Rules to Keeping Your Data - Backup... Backup... Backup!
Last night, I decided to update my live Drupal 6 multi-site setup. My development version is continually running the latest version of the Drupal core code and modules, but my live setup was slightly outdated. I'd also re-organised my 'sites' structure slightly on my development setup, and found several modules on the live server that I wasn't using. So, I decided to remove everything from the live server and replace it with the shiny up-to-date version from my development setup.