File services consolidation
At the top of the list of immediately accessible green storage options is file server consolidation by implementing a NAS. Simply reducing the number of file servers required by the enterprise can cut power costs.
However, more than just NAS is required. Most data centers already have purchased a NAS product to consolidate file services. The weakness of traditional NAS solutions is that they operate with individual standalone storage controllers that cannot be virtualized. Thus, as the need for more I/O capability or storage capacity grows, the traditional setup calls for an organization to add additional separate controllers. This leads to managing independent islands of NAS systems. So over the course of time, that initial effort of file server consolidation leads to distributed NAS systems, in essence recreating the same problem that NAS was meant to solve.
The multiplication of NAS systems is a real-world concern, especially considering that unstructured data (file data) is the fastest growing data set in the enterprise today. Consolidating to a traditional NAS is then not a long-term strategy but merely a Band-Aid, because of its lack of ability to scale in a way that can be practically managed. Traditional NAS should not be considered as a long-term solution to lowering power consumption.
Virtualized NAS cluster
If a traditional NAS system is not the solution to green file services, something different is needed -- a virtualized NAS cluster. This is a grid of NAS controllers that provides virtual file servers within individual NAS nodes. This technique allows for scaling across NAS nodes to address performance, scalability, and redundancy concerns while at the same time scaling down to provide granularity. Virtualized NAS clusters address the growth vectors that most data centers will experience.
In a virtualized NAS cluster, now offered by vendors like Isilon and ONStor, with NetApp planning an OnTap GX product this year, each virtualized NAS controller is a node in a grid that presents a single point of management and control. When additional I/O performance is needed because of user growth or increased data loads, another virtualized node is added to the cluster. That new node is now managed with the other nodes in the grid; no separate management point is required. If more capacity is required, more physical capacity can be added to the cluster.