07 Dec

Why Your Data Center Power Usage May Change

The following excerpt is from Datacate’s Colocation Survival Guide – get the full Guide here.

Your colocation is installed in the data center, and is up and running. Time to sit back and enjoy the fruits of your labors, right? Well, yes mostly. But there are some ongoing responsibilities that you will need to handle, beyond the obvious tasks of system administration and maintenance for your servers (which we will not delve into here). There are aspects of your colocation that will require some attention from you on a periodic basis.

Power utilization is rarely static in the data center, even when no changes to your equipment set have been made. Modern servers and related equipment are designed with power efficiency in mind. This means that power use by system components will be automatically ratcheted downward during idle periods (unless you have overridden this feature). But this also means that power usage will rise as the system spins up in response to increased demand. Because of this, power usage will wax and wane. In the long view most collocated hardware transitions to full production in a gradual way over a period of weeks or months – and power demands grow over that same time period.

The takeaway is this – you will need to monitor how your power usage changes over time. You certainly don’t want to overload your power circuit, and if your usage is poised to exceed the power allotment in your service contract, you’ll want to know that so you can make arrangements to address that issue, either by purchasing more power, or by making changes to your equipment in order to conform to your power allotment. Data centers must be strict about load levels on power circuits in order to conform with electrical and fire codes, so don’t expect an exception to be made on your behalf – they will unplug one or more of your servers without prior notice if that is what’s required to mitigate a dangerous overload condition!

If you have a full circuit, the facility should be able to provide you with power usage stats. Many PDUs have an LCD display built in to show power draw, and these “metered” PDUs will often times also be capable of remote monitoring, allowing power usage to be gathered and graphed over time. Failing all that, you can provide you own power usage monitoring device so you can keep any eye on things.

Many modern servers have a built-in IPMI (Internet Protocol Management Interface), which gives you remote “backend” control and monitoring for your server, including monitoring of power usage.