There are two ways to test an rsnapshot configuration (rsnapshot.conf) without actually running it:

• rsnapshot configtest checks if the configuration file is syntactically correct.
• rsnapshot -t <interval> prints all commands rsnapshot would execute for a specified backup interval without actually running them; this allows a careful inspection if commands look as expected (correct path specifications etc.).

All commands have to be run as root.

Source

• StackExchange: Can I do a "test run" with rsnapshot?