Atmos: Cloud Optimized Storage

With the announcement of Atmos today, EMC has also introduced a new class of storage: Cloud Optimized Storage.

This means there's a new acronym in town: COS.

For those of you already overwhelmed by the storage industry's use of acronyms, sorry 'bout that!

For those of you trying to understand what COS is, allow me to offer a definition. Think of COS in terms of the evolution of three storage system acronyms over the last ten years.

SAN ->  NAS ->  CAS -> COS.

What follows is a brief description of this evolution in terms of value to the customer: 

SAN Value = Centralized, secure multi-tenancy for blocks.

NAS Value = Centralized, secure multi-tenancy for files.

CAS Value = Centralized, secure multi-tenancy for objects (content + metadata).

COS Value = Globalized, secure multi-tenancy for content with rich policies.

In my mind the two distinguishing values that Cloud Optimized Storage adds to the party are summarized by using the words "Globalized" and "rich policies".

• COS implies that the storage is globally accessible. The conventional understanding behind SAN, NAS, and CAS systems was that they were "frames" or "racks" that lived within the walls of a data center.  Cloud optimized storage systems are geographically disperse yet managed as a single entity.
• COS also implies that rich metadata glues everything together. Centera introduced the option of appending metadata to content; COS introduces the imperative of attaching policies to content.

The Special Sauce of COS

Rich metadata in the form of policies is the special sauce behind Atmos and is the reason for the creation of a new class of storage system.  Atmos contains five "built-in" policies that can be attached to content:

• Replication
• Compression
• Spin-down
• Object de-dup
• Versioning

When any of these policies are attached to Atmos, COS techniques are used to automatically move the content around the globe to the locations that provide those services. Customers can place content into Atmos (using REST/SOAP or CIFS/NFS/IFS) and then associate that content with one of the built-in policies.

The Atmos architecture also allows for extensible policies. Customers that want to specify policies outside of those natively offered by Atmos can develop their own.  For example, picture a customer that wants to add "Cheap Power" as a policy; Atmos can be programmed to globally move content to a location with the cheapest power rates.

Let's Stop There

When it comes to how the Atmos software has been built, there's much more to say. I'll be back with more detail about how this thing has been built. I'll also do some comparative analysis of COS against conventional SAN/NAS/CAS technologies. Covering these items in this post, however, would take away the emphasis from this straightforward definition of COS:

Cloud Optimized Storage: global storage with a policy focus.

Steve