Assuming a 70% capacity model (we don’t want to go above 70% of the total capacity of our storage system), total storage we will need: 1.5 petabytes / 0.7 ~= 2.14 petabytes
@Design_Gurus - How did you come up with 70%?
You can consider the 70% standard practice. It just means, you don’t want your system to be at 100% capacity when all the work is completed. 70% is a good balance between the server having enough load and still having enough resources to operate efficiently. 70% is just a choice, you can make it 80% or 20%, it’s up to you.