You're missing the point about Google.
Google doesn't use BSD or NT or OSX or anything like that. They are all far too primative for what Google needs.
Google doesn't use primative RDBMS systems like Oracle or MS SQL Server... Larry Elison and Bill Gate should be worried... VERY worried...
These guys are doing something WAY different...
Google's architechture is based on a more common sense approach where SERVERS FAIL. And they don't care.
They use multiple servers to replicate data across all of them and when 1 fails - they trash it. No mess... no fuss... Junk the crap. They can do this because their data is replicated across multiple servers and the just stick in a new box with their own OS and their own software, replicate the data again to the new box and TADA~! Everything is done.
It's got nothing to do with the storage capacity. Storage is expensive no matter what you do. BUT... They have a better data storage strategy than MS or IBM or Oracle. This lets them use storage RELIABLY which is the biggest problem.
The cost will be offset by ads and things. EVERYONE advertises on Google.
Those guys have some slick stuff happening.
The next version of NT will address this issue in the new NT file system.
I haven't heard about anything like it coming from the *NIX community... Seems like they are stuck in their own little user-unfriendly world.