[CentOS] distributed storage/home-made cloud recommendations

Hello listmates,

This is not specifically CentOS-related - though I will probably execute
this design on CentOS if I decide to do so. It will certainly be some kind
of Linux.

At any rate, here's my situation. I would like to build a fairly large
storage solution (let us say, 100 TB). I want this solution to be
distributed and redundant. I want to be able to lose part of the machines
involved and still stay operational (the bigger part, the better). I would
prefer to avoid having to buy large servers to accomplish this task.

What I am soliciting here is thoughts, reports from experience,
recommendations, etc.

Thanks in advance.

Boris.