After the world ended you found out someone, (a rich person) made a copy of the internet before the end. (reason not important)
What is more believable:
1 - she has a massive 10-lvl subterranean basement, full of data drives holding all 100+ zettabytes. (100 trillion gigabytes)
2 - she has some secret storage format that rich people can buy but the public doesn't know about, so it's just 10 to 12 Rack towers.