But it's not just a question of Nas -- firms need greater levels of virtualisation throughout all of their storage infrastructure. What is popular about these two concepts is that you achieve a higher level of intelligence, ease of management and higher utilisation of the physical storage.
Nas and San [storage area network] environments have done a great job of networking your host systems to your single storage systems, but the storage systems themselves aren't networked with one another. The whole point of networks is to make everything a peer; everything can talk to everything else. But, that isn't true in our storage universe where we focus on host systems accessing individual storage systems.
What Fan does is 'network the networked storage' so that you have common communication between storage devices. This allows users to move data between systems for load balancing or tiering. I can replicate heterogeneously. I can create a federated storage view of all storage systems to improve access and management. The power comes when using storage devices in concert with one another.
These are new concepts in an emerging area of technology, but ultimately this is where storage networking is headed in general.
Check out the entire Nas FAQ guide.