All configuration settings for an entire farm are stored in a single SQL database. For this reason it is recommended that the database reside on a reliable server in the farm, or better yet on a separate dedicated database server set up with its own redundancy system (such as a Microsoft Windows cluster).
Without a reliable server or dedicated database server, the entire farm will no longer be able to make any configuration changes, and stopped trackers will not be able to restart if the Symphony server that contains the database fails.
All Symphony servers in a farm must be granted access to the centralized configuration database. To enable remote access to the SQL server, refer to the Installation guide.