I was at a customer earlier today and they are getting a 23:1 consolidation ratio by moving to the latest and greatest blade server platform running the newest virtualization software. This is a great scenario, but it brings up a good point most people never think of… converting 90 servers to 4 or 5 blades takes an environment and reduces it by 95%. That is 95% of the machines will be moved out. This might not sound like a big deal but walk into your data center and look around. Now imagine 95% of everything disappearing. For most people making a change like this means radically rethinking the data center infrastructure.
Traditional data center power and cooling designs are not optimized to support a high density computing environment. The problem this creates is completely inefficient cooling. Most A/C units are designed to run on a continuous or near continuous duty cycle. When the BTU (heat) load is reduced so dramatically the air cools much more rapidly. The A/C unit cycles off and on repeatedly taking a major toll on the gear. The other side effect (and I have personally seen it happen) when the air is cooled so rapidly condensation forms on the things closest to the A/C unit. The best bet is to redo the A/C unit at the same time you do a large scale consolidation.
The other piece of equipment that is negatively effected is the UPS (Uninteruptable Power Supply) system. These are typically designed to run best when they are at 50% load or higher. Once the load drops much below 50% the efficiency drops significantly. Most people do a consolidation as a way to reduce power consumption, but if your UPS wastes as much or more power than it supplies much of the savings you achieve from consolidation are mitigated. This again takes a large toll on the hardware.
The best thing you can do is to look art what the new load will be and invest in newer UPS and Cooling technology. There are vendors out there (one in particular comes to mind) who make products that are meant to scale from small environments to large ones without forklift upgrades. For those who don’t know, a forklift upgrade is the kind where you forklift out the old one and bring in the new one.
The good news is most of the old technology in the areas of cooling and power is not very environmentally friendly. Besides that almost none of it was very manageable. So you have an old box that does what it does and gives you almost no information about it. This is not a good match for the new virtualized, optimized environment you are building. You need dials, meters and monitors to ensure everything in your data center does what it does.
The important message is this: Disruptive technology disrupts everything around it. Remember you need to consider the whole data center environment.
