Does it back up the deleted blocks on virtual disk using VDP?

Hi, All

Here is my steps:

1. create VM with one OS virtual disk, whose type is thin privision, and whose size is 16GB.

2. install linux OS, the size of OS is about 3GB.

3. and then add new 8GB data.

4. and then delete the 8GB data.

5. to use vdp to back up the VM, from log, i find it backed up 11GB data.

i have a bit confusion, why it backed up 11GB data, i have only 3GB data in my VM, does it back up the deleted blocks(the 8GB data) by default? is that right?

and does it have some parameters to set to exclude the deleted blocks?

thanks

walker