HP Data Protector 9.05 With Thick Provision Eager Zeroed disks

Hello,

We have Vmware Vcenter 6.0 integrated with HP DP 9.05 as, we configured full backup jobs for VMs with Thick Provision Eager Zeroed disks.

The backup take the whole disks size as backup not the used space. (Ex: SCSI disk with total size 100GB, used space 20GB, the HP DP take as backup the 100GB)

How can full backup VMs and take only the used space with this type of disks ?

Please advise,