Thanks so much for your reply :)

You helped me a lot in understanding the beginning steps that I should plan for before going on with the hardware refresh 

I'd like to ask you more questions if you don't mind please 

What if after I completed the migration successfully to the new hardware and I want to configure new HP D2D appliance to be my main backup library ? Is there any recommendations and what are the steps or docmunets that shows the steps of configuring the new D2D appliance to be my main destination instead of the old tape library which will be decomissioned 

Second question :

I have a new tape library as well which I want to take an offsite backup to 

so what do you recomment for me : to have a seperate backup job which take the same backup afterwards to the tape library so having two seperate jobs for the same backup one to the D2D and the other to tape library ?

or 

there is an option on the netbackup which enable me to juct copy the backup from the D2D directly to the tape library without having an impact on the client and having the same backup twice on each same client ? and if so is there a specific license needed for such feature?

Thanks again for your help 

Thanks so much and Best Regards,