A Replication Agent is needed for the RSSD if the Replication Server is the source for any route.
If Replication Server is the source for any route, Replication Server distributes some of the information in its RSSD to other Replication Servers.
The RSSD is dedicated to the Replication Server that it supports; do not use it to store user data. However, a single data server may contain the RSSD and user databases. The database device space for the RSSD must be at least 20MB (10MB for data and 10MB for the log). It is best to put the database and the database log on separate devices.