The SQL Server support team just announced the release of a backup simulator. Many 3rd party utilities that do backup like IBM Tivoli, Symantec BackupExec, Quest Litespeed, Redgate SQL Backup etc. use the sqlvdi.dll to communicate to SQL Server and this allows you to simulate that activity. So if you want to test how your system reacts or more importantly need to troubleshoot issues associated with this activity or dll this is the answer. Have a look: Backup Simulator
Andrew J. Kelly
Solid Quality Mentors