Tail-Log Backups

>> If the database is ONLINE and you plan to perform a restore operation on the database, before starting the restore operation, back up the tail of the log using WITH NORECOVERY:

BACKUP LOG database_name TO WITH NORECOVERY

>>If the database is offline and does not start.

Try to take a tail-log backup. Because no transactions can occur at this time, using WITH NORECOVERY is optional. If the database is damaged, use WITH CONTINUE_AFTER_ERROR, as follows:

BACKUP LOG database_name TO WITH CONTINUE_AFTER_ERROR

If the database is damaged, for example, if the database does not start, a tail-log backup succeeds only if the log files are undamaged, the database is in a state that supports tail-log backups, and the database does not contain any bulk-logged changes.