The greater the complexity of your computing ecosystem, the more likely you'll derive benefits from a utility model. If enterprise storage for you really means "enterprise," it is something you should consider.

The emerging utility computing models offer many benefits under a variety of circumstances, but utility computing really shines when demands fluctuate. One hundred users kicking off different processes that run on multiple servers and accessing networked storage in a dynamically changing setting are much more likely to get value from utility computing than 1,000 users in a comparatively static environment.

A utility model assumes that the infrastructure provisions and manages services and assets on an as-needed basis. "On-demand" is the preferred marketing parlance of course, but I am starting to think that perhaps "as-needed" may be a more suitable term in a managed environment. This is because, in a managed environment, "need" would be determined by policy, not merely demand.

It is important to note that in complex environments this is likely to be no trivial task.

By way of example, as the amount of networked storage increases, the impact of the networks themselves takes on an increasingly important role in calculating storage I/O. Thus, as most networks are relatively non-deterministic, storage I/O that was once easily determined on a dedicated storage bus becomes harder to predict on a network. Other traffic on a network impacts your I/O demands, and your I/Os impact the network.

This of course becomes an even more demanding situation as IT resources are reconfigured to meet changing needs. Even if the new pathways are predetermined the task of bringing them on and offline certainly would be a daunting one.

Daunting, but not impossible.

Two technologies would seem to be fundamental to the on-the-fly provisioning that is required here: virtualization and automation, both discussed often in this column. But automation and virtualization of what?

It is a good bet that to get the most out of a complex system you will have to manage more than just the storage.

One simple but useful way to look at IT is to divide it into three broad categories of assets: servers, networking and storage. A completely managed computing utility should be able to virtualize and automatically manage across all three categories, getting the most out of all the components as they operate individually and also as they interact with other systems.