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,
    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?

  • Is this for multiple or just a single database? Is this production? AFAIK the only way to get more data is to use a DAC connection in single user mode - if you're up for that. Commented May 31, 2022 at 14:48

1 Answer 1


A log backup is not based on the most recent full backup. It is based on the most recent log backup.

I.e., you can "skip" a full or differential backup when you restore log backups, as long as you have an unbroken chain of log backups.

As for your particular issue: Work with the backup software/vendor and see if you can make it perform the snapshot backups so they are seen as COPY_ONLY by SQL Server. Possibly a setting in your backup software.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.