Features of smart PDU in data centers

Over the past few years, the overall power density (kW per rack) in data centers, both corporate and commercial, has increased significantly. Ten years ago, a typical server cabinet consumed 1-2 kW, and the PDU units installed in it were ordinary extension cords, different from home appliances except by a large number of power outlets. Today, server cabinets require much more power from a PDU. The typical level is 4-5 kW, but quite a few cabinets are filled with equipment that consumes 5-9 kW. In operation there are cabinets for 10-25 kW and even more power.

The AFCOM Institute identifies four power levels per rack:

- low - up to 4 kW;

- average - 5-8 kW;

- high - 9-15 kW;

- extreme - 16 kW and above.

This classification was proposed in 2014, and already today the “extreme” level for many companies looks quite usual. According to the Uptime Institute, 41% of data centers already use racks with a capacity of over 20 kW.

Reliability

The need of data centers for “smart” PDUs is caused not only by economic issues, but also by tasks related to ensuring a high level of reliability. If racks use PDUs without a power monitoring function, of course, you can manually measure your consumption with a multimeter. But this procedure requires quite a lot of time, and even worse, it significantly increases the risk of possible incidents due to the human factor, since the process requires a certain intrusion into the infrastructure (opening the cabinet door, connecting a measuring device, etc.). Moreover, since such measurements can only be carried out from time to time, they do not allow to detect consumption peaks, as well as to calculate the total power consumed by IT equipment over a certain period.

As each new generation of IT equipment increases power requirements, the use of conventional (non-smart) PDUs increases the risks more and more. Without accurate data of power consumption, the IT administrator will not know if you can still install servers in this rack, and if so, how many. Upgrading servers or even updating software can change its power consumption, and the lack of operational data is fraught with exceeding the permissible load on the rack with the already mentioned consequences (overheating, shutdown of the machine, etc.). As for adding new servers to the rack without the availability of information on current energy consumption can lead to the most negative consequences.

Efficiency

Modern data centers often use the PUE metric that our previous article was about to measure performance. However, we must understand that the value of PUE characterizes only the efficiency of the engineering infrastructure of the data center. An important task is to evaluate the performance of the computing environment itself, servers and data storage systems. To help solve this problem will help modern PDU units with the ability to measure the energy consumption of individual pieces of equipment.

The availability of data on energy consumption will allow you to assess how much it changes when the operating environment, software updates or server hardware components change. Having obtained such data, specialists can use them to correlate the performance indicators of IT equipment with energy consumption indicators. The resulting data can help assess how effective this or that upgrade is, as well as plan the development of the computing environment.