I recently had a problem with the 'model' database remaining stuck in RESTORING state and keeping SQL Server from starting up. I eventually recovered by restoring system databases from a 10 days old backup.
To arrive at that solution, I carefully went through the server's error logs. Briefly, SQL Server was successfully restarted on 3-Mar as part of a week system reboot to integrate new updates. On 5-Mar a backup of all databases was taken, including the system databases. On 10-Mar, during the weekly reboot, SQL Server failed to start, and all subsequent attempts at recovery failed.
Eventually, I decided to restore the system databases from 2-Mar, not just the 'model' db, but also, master and tempdb. In fact, all attempts at restoring only the 'model' db had failed.
It seems reasonable to assume that something happened during backup; that whatever happened did not just affect 'model' but must have created a problem with 'master'. At this point, I'm really thinking there is a chance that the errors thrown (Events 3402 and 1814) are misleading and only consequences of the real error.
Anyway, that's all speculation at this but I have to start somewhere. Hence my question: is there any reason why a backup would leave the source database in 'RESTORING' state.
Regards,
Philippe