Bring back to restoring state an online database

Question

I configured logshipping for a database. I did some tests and tried a controlled failover.

During log shipping secondary db is in restoring state.

To have a controlled failover i stopped the primary database. then i put online my secondary db with:

RESTORE DATABASE AdventureWorks WITH RECOVERY

Then stopped the log shipping jobs in the secondary server and pointed my application (a website) to the secondary server.

Everything worked as expected. Now i want to bring back online the primary server: i started the primary server then i pointed the application to the primary server and restarted the logshipping jobs in the secondary server. I only need to set the secondary db in restoring mode but the command:

RESTORE DATABASE AdventureWorks WITH NORECOVERY

and it gives me the error:

The database is already fully recovered. RESTORE DATABASE is terminating abnormally.

do i need to restore a backup in the secondary anyway?

which are the best practice in this case? how do i revert to the initial situation?

Solution

Once you recovered the database, the primary and the secondary diverged. So, you have to restore the LS secondary from a fresh backup of the primary and re-establish LS.