VDC_GetPosition

This command is supported if VDF_Position or VDF_RandomAccess is set in the configuration. The position field must be provided on command completion.

If VDF_RandomAccess is specified, the position returned to Microsoft® SQL Server™ must always be a zero-origin byte offset from the beginning of data. If VDF_RandomAccess is not specified, the position is treated as a block address.

Microsoft Tape Format (MTF) requires a Physical Block Address (PBA) in several of its fields. SQL Server does not support tapes that do not return block addresses. SQL Server chooses logical block addressing before physical block addressing when both are available. Because pipes do not provide PBA, the virtual device interface permits client configurations without positioning support. In this case, SQL Server creates a PBA based on the media's apparent position.