Drush sql-sync is a very easy way of grabbing a copy of a Drupal database from one site and installing it on another site. The normal application of this task is to copy the database from the production site to your local environment for facilitate local development. There are one or two steps to sort out before you can use the command
This post assumes you have Drush 8 installed on your machine as Drush 9 uses a different syntax for sotring Drush aliases. This also assumes that you have setup SSH key access to all servers you need to get access to.
Setting Up Aliases
The first thing you need to do is set up your Drush aliases, this allows you to connect to the remote Drupal instance from your local machine. Drush aliases are kept in your ~/.drush directory. To see what aliases you have on your system use the command.