Labor and Power Savings
The main reason to use an intelligent PDU is to measure and monitor power usage. And the main function of these devices, including the Dominion PX, is to provide alerts when a system begins to use power above an allotted threshold. Such events can be warning signs of overutilization or an electrical or mechanical failure in the monitored resource. I was able to easily monitor my server systems and network switches that support my VMware ESX cluster using the Dominion PX Web-based interface. I could set minimum and maximum power utilization thresholds, and the Dominion PX uses industry-standard SNMP traps to send alert conditions. This made it easy to integrate the data into existing management tools.Another good use of the Dominion PX is in remote locations where IT staffers are not routinely present. Using the GUI and when logged in as a user with sufficient privilege, I was able to select individual outlets and cycle the power, forcing a reboot of the device connected to that outlet. This is especially cost-effective in situations where a hard reset would require a truck roll. The Dominion PX answered a question that had been floating around eWEEK Labs for a while: Just how much power load are we placing on the circuits running our equipment? Much of our equipment is only lightly loaded for much of its uptime. The Dominion PX let me know that three IBM e325 servers and a 1TB Dell disk array drew 7.9 amps of 120-volt power from a 20-amp circuit when idling. Of course, the voltage for these devices varied widely, and the Dominion PX displayed that data as well. Using the Dominion PX, I was able to move away from relying on the circuit breaker to get an idea of the electric power needs of my test systems. This would be especially useful information for IT managers for capacity planning. And having more precise power utilization records should help IT managers apportion utility costs when charging back operational costs to business units.
I also used the temperature and humidity probes to monitor my rack-mounted computing resources. The temperature probes are the size and shape of a USB drive. I used zip ties to secure the probes in the air-flow intake and exhaust at several levels of the rack. Using the data supplied by the probes, it was easy to see the real-time air temperature and relative humidity surrounding the equipment. Again, the Dominion PX allowed me to set minimum and maximum thresholds for measurements reported by the probes.