VDF_SnapshotPrepare (0x0400)

Used with BACKUP WITH SNAPSHOT operations. When this bit is set, SQL Server will send a VDC_PrepareToFreeze command prior to freezing the database files. This allows the VDI application control over the timing of the freeze. It is particularly useful when coordinating snapshots of multiple databases.

This feature bit is only defined in Microsoft® SQL Server™ 2000 Service Pack 2 and later. In earlier versions of SQL Server, the bit is ignored and no VDC_PrepareToFreeze command is issued. The snapshot proceeds immediately to the frozen state and a VDC_Snapshot command is issued.

For more information, see SNAPSHOT Support