A NetBackup for Microsoft SQL Server agent backup fails sporadically with status code 6.

Problem

A NetBackup for Microsoft SQL Server agent backup fails sporadically with status code 6 (the backup failed to back up the requested files) reported.  Most often, but not always, this occurs in larger, busy environments.

Error Message

Specifically, the following error is returned in the dbclient log on the SQL server:
INFO No rows found in SQL request <SELECT replace(convert(varchar, s.backup_start_date,111),'/','') + replace(convert(varchar, s.backup_start_date,108),':',''), replace(convert(varchar, s.backup_finish_date,111),'/','') + replace(convert(varchar, s.backup_finish_date,108),':','') FROM msdb.dbo.backupset s inner join msdb.dbo.backupmediafamily m ON s.media_set_id = m.media_set_id WHERE s.database_name = 'BIGDB' AND m.physical_device_name = 'VNBU0-7568-11744-1347420635' ORDER BY s.backup_finish_date>.

Cause

This issue occurs because NetBackup is attempting to read a particular entry from a system table in SQL server.  That entry, however, is related to the backup itself and, on a busy server, may not be generated in a timely fashion.  By default, NetBackup will retry (to read the entry) for 5 seconds and, if still unable to read the entry, the above message is returned and the backup fails.

Solution

The formal resolution for this issue (Etrack 3060398) is included in the following release:

• NetBackup for SQL Agent 7.5 Maintenance Release 5 (7.5.0.5)

NetBackup 7.5.0.5 is now available - please access the Related Article linked below for download and README information. 

Applies To

SQL Server 2005

SQL Server 2008

SQL Server 2008 R2

NetBackup 7.1.0.x or 7.5.0.x (through 7.5.0.4)