A petabyte is equal of 1000 terrabytes (a terrabyte is equal to 1,000 GB!). That’s the size of a 32 YEAR long mp3 file!!
The movie was shot in 3D and rendered in one of the most powerful data centers in the world. Its computing core adds up to 39,000 processors and 103 terabytes of RAM. 300 million dollar budget on Avatar was spent on storage