Case Study: Electrical Power And Disaster Recovery

Case Study

Electrical Power and Disaster Recovery

Donald Bowen

SE591 - Stuart Gold

Keller Graduate School of Management

2/15/2011

Overview

Electrical power is probably the most unstable of the environmental factors facing the data center. No power, no data. Emergency power strategies should be one of the most important parts of your disaster recovery (DR) planning.

How can good power protection be attained?

The most important way is through intelligent power planning. The goal is to minimize the potential for component failure. One way to do this is to identify and address potential single points of failure. This can be achieved through power audits and assessments. According to Toigo (2003), to reduce obvious risk potentials, be on the lookout for:

* "Daisy Chains" of electrical cords and power strips that indicate circuit overloading.

* Outlet covers with obvious charring that may signal a past short circuit or overload.

* Computer monitors with noticeable movement in the display tube and/or hums or other distortions in audio devices such as desktop speakers or phone handsets.

* Lights dimming on and off.

* Logs of data communications errors.

* Records of abnormal (or frequent) component failure and replacement cycles.

* User reports of any abnormal equipment operations.

You may want to add circuits to prevent overloads or shift certain devices to alternate circuits to reduce noise.

Redundancy vs. Replacement

One example of redundancy is to duplicate power supplies. That is, to obtain power from two separate power substations in order to provide a backup if the primary supply fails. The idea is to duplicate as many connections as possible to provide an alternative path of connectivity in the event of a breakdown.

Replacement is used to provide protection when redundancy will not work. An example would be to generate your own power with generators, but you would need to make provisions for fuel and necessary switching equipment. This is probably the most expensive solution.

Is the need to protect our power resources vital to American society today?

Yes, we have become a technology dependent society. Today, more than ever, we need our power resources in order to live our daily lives. From our computers and televisions and even to our automobiles, we need to protect our electrical power.

Quality Assurance

Network based power protection and monitoring is the ideal centralized solution. Simple Network Management Protocol (SNMP) used on a TCP/IP network enables power protection devices to communicate their condition through management information bases (MIBs). MIBs are small databases that update themselves. An SNMP program reads the contents of the MIBs and reports to a centralized management console. This allows more devices to be checked by less people (Toigo, 2003).

What are examples of different types of power protection?

Here are some examples of the different building blocks of power protection. We begin with the UPS (Uninterruptable Power Supply). UPS systems are highly specialized electrical equipment designed to prevent temporary or intermittent power fluctuations or failures from affecting the continuing computer operations. A UPS system can provide cleaner power than what is available from your utility company.

A UPS can protect a computer against four different power problems:

* Voltage surges and spikes - Times when the voltage on the line is greater than it should be.

* Voltage sags - Times when the voltage on the line is less than it should be.

* Total power failure - Times when a line goes down or a fuse blows somewhere on the grid or in the building.

* Frequency differences - Times when the power is oscillating at something other than 60 Hertz

There are two common systems in use today: standby UPS and continuous UPS:

* Standby UPS - Runs the computer off the normal utility power until it detects a problem. Then it very quickly (in 5 milliseconds or less) turns on a power inverter and runs the computer off of the UPS's battery. A power inverter turns the DC power delivered by the battery into 120-volt, 60-Hertz AC-power.

* Continuous UPS - The computer is always running off of battery power and the battery is continuously being charged. If the power fails, the battery provides power to the inverter. There is no switch-over time in a continuous UPS (How does a computers uninterruptible power supply UPS work?).

Here are six key steps to maximizing power system availability:

1) Standardize on a high-quality UPS. Select a manufacturer with significant experience and a proven in-service success record. Look for designs with internal redundancy of key components, multiple power paths, higher quality components and manufacturing processes that incorporate rigorous quality tests.

2) Choose UPSs with multiple internal power paths. Better UPS designs provide multiple power paths for additional redundancy, including such features as a static bypass switch and manual or automated maintenance bypass.

3) Look for a UPS that is capable to support your IT equipment. Some low-cost UPS designs may not be able to properly support your load, causing IT equipment to reset, corrupt data, or shut down. Double-conversions and high-efficiency, multi-mode UPSs supply conditioned power well within the acceptable voltage and frequency range of the IT and industrial equipment they support.

4) Deploy redundant, parallel UPSs. This strategy establishes redundancy of power paths, electronics, and battery modules to create the highest reliable protection.

5) Look for features that improve MTTR (Mean Time to Repair). Select modular system designs and UPSs with easily serviceable parts, such as hot-swappable batteries and electronics. Ultimately, MTTR has a far more profound impact on availability than MTBF (Mean