VTL and OST Netbackup

Good Day Geeks !

We have DD4500 and we using it both as OST and VTL. NOw what we have done is we have created 100 Tapes of 800Gb capaicty . I am aware Data Domain will deduplicate the data in the backend where Netbackup at front end will keep on using new tapes considering them as normal physical tapes.

Now my only concern is that our DD capacity is 130 TB and I have consumed 80TB for VTL which in actual is not being used by data I am backing up on VTL on data domain. Would i be able to use the whole data domain space or i can only use 50 TB for Open storage ?

Thanks,

Pranav Batra