Differential or log backup fails with the Backup Exec SQL Agent was not used to create the last full, differential, or log backup of this database

Problem

Differential/Log backup of SQL databases fails with the following error. 

Error Message

Backup Job Log shows:

V-79-57344-33960 - 0xe00084a8 - A log backup was attempted on database <DatabaseName> that is not configured to support log backups. To change the configuration, use the SQL administration tools to set the recovery mode to Full. A new full backup should be performed if this setting is changed before a log backup is run.

V-79-57344-867 - 0xe0000363 - The Backup Exec SQL Agent was not used to create the last full, differential, or log backup of this database. You must use the SQL Agent to run a full backup before you can run a differential backup or transaction log backup.

Cause

The Differential/Log backup of SQL database may fail with the above mentioned error when running SQL backups in Backup Exec using the Full/Differential Log backup strategy.

When any backup application is used in conjunction with Backup Exec ( for example Veritas System Recovery or SQL internal backup utility ) then it may render the SQL Server differential or log backups unrecoverable, even though the differential or log backups showed that they completed successfully in the job log.

This issue occurs because the Log Sequence Number (LSN) for SQL is reset by the other backup application. So, subsequent differential or log backups performed by Backup Exec are relative to the other backup application instead of the original Backup Exec full backup. The subsequent differential or log backups are thus rendered unrecoverable by BEWS, because it is unable to use the backup sets created by the other backup application.

In Backup Exec 11D (post Hotfix 38) and later versions, a change has been made to the Backup Exec Agent for Microsoft SQL Server. Backup Exec now runs a reference check against the Microsoft SQL instance, to verify if the last database backup was taken with Backup Exec SQL Agent. This change helps maintain the integrity of the SQL backups.

Solution

1. Make sure no SQL backups run outside Backup Exec (including SQL in-built utility for Backups and Restores) as that would interrupt the continuity of SQL backups within Backup Exec schedule, causing the job to fail.
2. Open the SQL Management Studio. Navigate the database in question.
3. Right click on the Database, go to Reports, Standard Reports, Backup and Restore Events.

4. .Wait for the reports to be retrieved and select Successful Backup Operations.

5. You can now see the history of the successful backups of the database. Note the date and time, Backup Type, and Backup Name.