Last week I read a blog from BackBlaze about their custom made peta byte storage system. It drew lot of attentions from the geek community. It is really interesting to see how they made component choices and design decisions for their storage requirement. Here is the link to the blog posthttp://blog.backblaze.com/2009/09/01/petabytes-on-a-budget-how-to-build-cheap-cloud-storage
Cost comparison from various vendors is
Case design is quite interesting....
Google popularized commodity hardware and Amazon popularized low cost elastic storage and computing infrastructure. They brought in lot of real world confidence that "this kind of bold move will definitely work", Having boosted confidence by looking out those companies lot of new player going to come up with new refined low cost ideas and which will create enough trouble for big storage and other server vendors.