Ha. It's fun to throw these estimates around. While 16EB is a lot, let's see where a back of envelope estimate gets us. Assume that storage mostly follows Moore's law of doubling capacity in every 18 months. That is 2^6.667=97 in 10 years; let's say about 100X capacity in 10 years.

So in 10 years we will have 100x120TB = 12PB per disk. Put 8 of these disks in a 2-U unit and we'll have a 100PB box. Stack 10 of these units together in a rack and we'll get an 1EB storage rack.

Remember some file systems use couple bits off the 64-bit addressing space for other purposes. Shaving 4 bits off and we get 1.15EB. That's within the 10-year storage capacity estimate.

While present day Youtude might not have that much data, I'm sure when the 16K, 32K, and 64K videos come along the space will be filled up. Let's not forget the voluminous 3-D Lidar scan data generated by every iPhone when people start recording 3-D VR-Holodeck from their phones. Besides wouldn't it be cool to host an entire copy of the Youtude in your closet? ;)

Youtube has been estimated to have an amount of data in the exabyte range: https://www.quora.com/What-is-the-total-size-storage-capacit...

This was a few years ago, so it might be possible that Youtube has more data than what can be addressed with a 64-bit value.