We have a SQL Server 2014 Enterprise where the DIFF backups fail.
This is the error message we get:
Msg 3035, Level 16, State 1, Server sqltest, Line 1
Cannot perform a differential backup for database 'database1', because a current database backup does not exsist. Perform a full database backup by reissuing BACKUP DATABASE, omitting the WITH DIFFERENTIAL option.
After analysing the output of the following query we noticed that a third party tool was taking snapshot backups.
select top 20 bs.type,bs.database_backup_lsn,bs.checkpoint_lsn,bs.backup_start_date,bs.is_snapshot, bs.is_copy_only,bs.user_name from dbo.backupset bs where bs.database_name = 'database1' order by backup_start_date desc
According to Pinal Dave these tools use VSS to take a backup which is not a normal full backup.
What I don't understand is why LOG backups succeed? To my knowledge, they are also based on the last FULL backup.
Can somebody explain this difference to me?