When an SQL Server or SQL Express instance is prepared for Backup Exec Database (BEDB) and the service credential is Network Service, Backup Exec installer would prompt the following warning.
The service for the selected SQL server instance is currently running with NT AUTHORITY\NETWORKSERVICE account credentials. The credentials must be changed to use the LocalSystem service account credentials. If you cannot change the service account credentials for the selected SQL server instance, then you must select another SQL server instance.
Do you want the Installation program to change the credentials for the specified SQL instance?
Even if yes is answered to the question, Backup Exec installation program would not change the service credential.
This follows that database maintenance fails to create a backup(dump) of BEDB.
Application Log Events:
Event ID: 18204
BackupDiskFile::CreateMedia: Backup device 'C:\Program Files\Symantec\Backup Exec\Data\BEDB.bak' failed to create. Operating system error 5(Access is denied.).
Event ID: 3041
BACKUP failed to complete the command BACKUP DATABASE BEDB. Check the backup application log for detailed messages.
Source: Backup Exec
Event ID: 57348
Backup Exec Alert: Database Maintenance Failure
(Server: "servername") (Job: "Database Maintenance") Summary of database maintenance activity:
Maintenance has failed: 10, Dump database failed
Total elapsed time: 00:00:31
This issue is resolved in Backup Exec 2014 or later versions.
To resolve this issue and receive the new Backup Exec improvements please upgrade to the current version of Backup Exec.
NOTE: Symantec continues to focus on the current release and future releases, there are no plans to address this issue by way of a patch or hotfix in earlier versions of the software at the present time. Please contact your Symantec Sales representative or the Symantec Partner for upgrade information including upgrade eligibility to the release containing the resolution for this issue. For information on how to contact Symantec Sales, please see http://www.symantec.com
WORKAROUND (Backup Exec 2012)
Manually change the service credential of SQL instance to LocalSystem or Administrator.