v8 - backuping up white space?

[frankive]

Not sure if this is related to v8 or not but we have a few small customers with extreme small servers (Hp Microserver).
The c: is 150GB but only used 30 GB
The d: is 300GB but only used 4 GB

The disc is dynamic .vhdx (2012 R2 Essentials host and vm)

I can see that the dynamic files (f.ex d:) is actually around 180GB large (even when there is just used 4GB data in my computer in the VM). The shadow copy is abuot 200MB.

Still Veeam is backuping up around 130GB if I run full backup.

Have tried to compact and defrag the .vhdx files but the drives still remain the same.
I think this could be more a Windows issue than Veeam.
But shouldn't Veeam see that there is no data to copy rather than the 4GB on the d: drive?

[Gostev]

How do you know it's white space? Remember that NTFS does not zero out disk blocks when you delete a file, actual disk blocks will still contain file data. You need to use sdelete or similar tools to really turn unused disk space into white space.

[frankive]

I dont know that, just assumed
What you say makes sense (as always). I think there has been pretty large files on some of the .vhdx (client backup) before we isolated them to a separate .vhdx file which we exclude from the veeam backup job. It must be these remaining data blocks which still consist file data that both the .vhdx file holds on too and also Veeam is taking backup of.
I will take a look at sdelete and see if that can reduce the size of .vhdx file and hopefully also the Veeam backup size.

Thanks.

[frankive]

I assume another workaround is to take the VM down, create a new .vhdx harddrive based on the existing drive. It will then just copy the data which is seen (hopefully)

[foggy]

If you just copy files to this new disk, then yes, the size of the backup will be much smaller.