I was recently involved in defining a backup strategy for multiple SQL Servers running in a vSphere environment. The latest version (1.5 U1) of VCB was being used along with the latest release (6.5.5) of NetBackup . Part of this process involved creating a matrix of Microsoft supported Windows/SQL configurations and the data consistency levels of these supported configurations. The chart below summarizes the current state of data consistency levels, when using VCB for Windows/SQL Server backups.
Microsoft does not support this combination of Windows and SQL Server. A combination unsupported by Microsoft.
This is the state in which a system would be found after a system failure or power outage.
This is the state in which all databases are in-synch and represent the true status of the application.
The customer, in this case, was not willing to assume the risk of crash consistent data for SQL Servers. With this particular VCB and NetBackup setup, the reality is that any Windows/SQL pair that does not provide application level consistency will either need to be backed up as a native SQL flat file backup or utilize the NetBackup SQL Agents. This decision would ultimately lead to additional spending in the form of either disk space or the purchase of NetBackup SQL Agents, and would add operational complexities with multiple backup strategies. There is also hope that NetBackup 7 may allow us to revisit this issue very soon and find a more singular approach for SQL Servers.
Note: This information is valid as of January 28, 2010 for VCB 1.5 U1 and vSphere 4.0 U1 editions.
As always, thanks for reading.