To backup the transaction log first you must have a working master database. Without the master database the sql server won’t start.
In this case use the KB 253817.
We all aware that a full database backup is the basis of our backup strategy.
So, what will happen when you create a new database on your production server because high level management need this a.s.a.p ?
You use the full recovery model to include this database in your backup strategy. Of course, the full backup will run as always later the day.
The requested department started to work with the new database. Hours later somebody reported a problem with the new database.
During investigation you find out that most of the data from the last hours are deleted and no longer available.
But, you are running the database in full recovery mode. You started with the recovery from the transaction log.
Normally this is not a big deal. This time it will not work.
Why ?
Although the database is using the full recovery model a full backup was never done.
Therefore the transaction log was reused by the SQL Server after reaching the end of the log file.
This truncation of the log file will also occur when you truncate the transaction log after the last full backup.
Above scenario may not be the best example but it show you the importance to do a full backup.
