The Challenges of Content Addressed Storage
Michael Kilian
Centera Chief Technologist
EMC


This talk will discuss Centera, a new content addressed storage (CAS)
device for unchanging information. Unlike conventional storage devices
(e.g., block or file systembased), CAS completely segregates the naming
of an object from its storage location. More to the point, the content
being stored actually defines the address of the object. This talk will
focus on the concepts behind CAS, and particularly Centera. Because of
features like a globally consistent address space for objects, CAS
offers a number of challenges.

a) How globally unique is a content address?
b) How can we implement the complete virtualization of storage CAS
offers?
c) How do we model reliability in a system that heals itself?
d) What are the programming model challenges?

CAS also offers many intriguing possibilities for future architectures.
Given the dramatic decrease in the cost of storage and the ease of
managing truly enormous (and distributed) address space with CAS, should
we bother throwing anything away? Should we now focus on temporal views
of storage? What happens when ubiquitous (and infinite) storage meets
ubiquitous (and infinite) bandwidth? Finally, how do we access storage
that is more self-aware of its own content?

By the end of this talk I hope you will not only be intrigued with a new
way of thinking about storage, but also challenged to think of new ways
of applying a new paradigm.