All night today (actually tonight), we’ve been on a production deployment call. One piece of the puzzle that, we assumed, but did not take into account is the switch back from SIMPLE to FULL recovery model. The required steps that need to be done after we make the switch back to FULL. We need to perform a FULL database backup after making the switch to maintain continuity in log chain.

Okay, this is the bigger picture.

We had a deployment tonight and in preparation for it, we took a note of all the steps and the duration it takes for each and a rollback plan if needed. One of the steps is to switch the RECOVERY model from FULL to SIMPLE during the deployment and switch it back at the end. But surprisingly we did not account for the time needed for the tasks related to switching back.

According to MSDN:

After switching from the simple recovery model

• Immediately after switching to the full recovery model or bulk-logged recovery model, take a full or differential database backup to start the log chain.

When we go to SIMPLE recovery model, the transactional log backup chain is lost. So, when you switch back to FULL recovery  model, you need to re-establish backup and TLOG backup chain. So we need to run a FULL backup before you can run any TRN LOG backups.

Glad to we have a team on the other side of the planet that can take over the rest of the deployment and send us an email when the backups are complete.

Hope this helps,
_Sqltimes