> I think you missed the point. Maybe I am thinking more broadly when imagine what it means to implement something like Spanner on top of S3. We know that Spa

> I think you missed the point. Maybe I am thinking more broadly when imagine what it means to implement something like Spanner on top of S3. We know that Spanner on top of S3 is not going to give you the same price/performance as building Spanner on top of Colossus while giving you the same semantics. You either relax the semantics a little bit, you pay out the nose for a lot of little files, or you find a durable place outside S3 to store the newest data. > At a high level, yes, you can implement systems like Megastore or Bigtable over S3. However, there are many details you must take into account. You cannot simply wave away the complexity and potential failure scenarios. Most of the complexity is the same whether you implement Megastore on top of S3 or on top of GFS. You can’t handwave it in either scenario. > If you essentially reimplement the system, why use S3 at all? It’s highly durable, highly available, and cheap (under certain usage scenarios). GFS is not available for anyone to use, inside or outside Google. Its successor, Colossus, is not available outside Google. They’re just not available.