I’ve just got email from Amazon introducing new storage option they have added to the highly popular S3 service called Reduced Redundancy Storage (RRS). This options actually downgrades S3 by removing data redundancy and providing lower cost than redundant S3. This option absolutely makes sense providing cost-effective solution for storing data which is not important (e.g. cache data) or is securely replicated somewhere else.

The funny thing about RRS introduction email from Amazon is the comparison numbers:

Amazon S3 standard storage is designed to provide 99.999999999% durability and to sustain the concurrent loss of data in two facilities, while RRS is designed to provide 99.99% durability and to sustain the loss of data in a single facility.

So RRS provides *only* 99.99% durability while standard S3 *all* 99.999999999%!