I'm backing up a virtual machine's disk in NFS storage on a vCenter 7.0.3u3. When I use QueryDiskChangedArea() and VixDiskLib_QueryAllocatedBlocks() to query the disk's changed data, it returns the data of the entire disk, and many of its data may be 0, I don't need these 0 data, what should I do to know which data is really useful? please help me?