Go to the SQL server and make sure that the BE remote agent service is running.  Also check the eventlog to see whether there is any failure of this service and the reasons.

Thanks pkh..

I have checked BE remote agent service status as well as eventlog

Following events are seen in the event viewer:

Event Type: Error
Event Source: Backup Exec
Event Category: None
Event ID: 57859
 
Description: An error occurred while executing the following query: "BACKUP DATABASE [Database_Name] TO virtual_device = "Database_Name

Event Type: Error
Event Source: SQLVDI
Event Category: None
Event ID: 1
 
Description: SQLVDI: Loc=TriggerAbort. Desc=invoked. ErrorCode=(0). Process=2180. Thread=4888. Server. Instance=QM. VD=Global\Database_Name___SQLVDIMemoryName_0

Acoording to this error found below technote

http://www.symantec.com/business/support/index?page=content&id=TECH128896

Please suggest to proceed....

Thanks..