In June and August of last year, I wrote a pair of columns in which I extolled the value of virtualization as a solution to excessive energy consumption. The primary benefit, as I described it, is that virtualization makes it possible to consolidate multiple applications onto a single server. That is, apps that currently run on dedicated systems can be moved en masse to a single server that consumes less power -- generally, far less power -- than that required by the dedicated servers.

This economy derives from two principal factors:

1) Modern servers are much more energy-efficient than their forbears. This is true in absolute terms and relative terms. In fact, in relative terms, such as watts per mips, today's systems are orders of magnitude more efficient.

2)

Until very recently, the need for IT to really include eco-concerns as part of overall strategy did not have universal appeal. Surely, sites located in areas such as southern Manhattan where power distribution is already running at maximum capacity have a grave problem. And likewise sites that need more room but have tight expansion constraints. For them, green has been a key preoccupation for a while.

For most other IT sites, however, the main driver for green has been cost reduction -- and until the last few months, the cost of energy was tolerable even if somewhat higher than budgeted. So, pressure existed to reduce unnecessary consumption, but not place the issue at the center of IT concerns. However, with oil now regularly surpassing $130 per barrel, there is no longer any

The golf expression "It's the rub of the green" means the equivalent of "them's the breaks." It refers to the fact that you're going to have your share of good luck and bad luck when your ball is on the green. Every so often you'll hit a divot or other irregularity -- and sometimes the results will be good, other times not so much. It's the rub of the green. Today, I want to refer to the expression in a rather different sense: when green rubs people and IT the wrong way. The world today is so prone to over-marketing, so accustomed to rapid cycles of surging popularity followed by a precipitous descent into oblivion that, at times it feels like the only sane way to deal with new trends is to tune them out. This applies even to green. Let's not forget that the