CompTIA Security_ Deluxe Study Guide_ SY0-201 - Emmett Dulaney [149]
Environmental Systems
Many computer systems require temperature and humidity control for reliable service. The larger servers, communications equipment, and drive arrays generate considerable amounts of heat; this is especially true of mainframe and older minicomputers. An environmental system for this type of equipment is a significant expense beyond the actual computer system costs. Fortunately, newer systems operate in a wider temperature range. Most new systems are designed to operate in an office environment.
If the computer systems you’re responsible for require special environmental considerations, you’ll need to establish cooling and humidity control. Ideally, systems are located in the middle of the building, and they’re ducted separately from the rest of the HVAC system. It’s a common practice for modern buildings to use a zone-based air conditioning environment, which allows the environmental plant to be turned off when the building isn’t occupied. A computer room will typically require full-time environmental control.
Environmental systems should be monitored to prevent the computer center’s humidity level from dropping below 50 percent. Electrostatic damage is likely to occur when humidity levels get too low.
Humidity control prevents the buildup of static electricity in the environment. If the humidity drops much below 50 percent, electronic components are extremely vulnerable to damage from electrostatic shock. Most environmental systems also regulate humidity; however, a malfunctioning system can cause the humidity to be almost entirely extracted from a room. Make sure that environmental systems are regularly serviced.
Environmental concerns also include considerations about water and flood damage as well as fire suppression. Computer rooms should have fire and moisture detectors. Most office buildings have water pipes and other moisture-carrying systems in the ceiling. If a water pipe bursts (which is common in minor earthquakes), the computer room could become flooded. Water and electricity don’t mix. Moisture monitors would automatically kill power in a computer room if moisture were detected.
Fire, no matter how small, can cause damage to computer systems. Apart from the high heat, which can melt or warp plastics and metals, the smoke from the fire can permeate the computers. Smoke particles are large enough to lodge under the read/write head of a hard disk, thereby causing data loss. In addition, the fire-suppression systems in most buildings consist of water under pressure, and the water damage from putting out even a small fire could wipe out an entire data center.
The three critical components of any fire are heat, fuel, and oxygen. If any component of this trilogy is removed, a fire isn’t possible. Most fire-suppression systems work on this concept.
Fire suppression is discussed further in this chapter in the section by the same name, “Fire Suppression.”
Power Systems
Computer systems are susceptible to power and interference problems. A computer requires a steady input of AC power to produce reliable DC voltage for its electronic systems. Power systems are designed to operate in a wide band of power characteristics; they help keep the electrical service constant, and they ensure smooth operations.
Real World Scenario
Simple Things Can Have Huge Consequences
Water can come from anywhere, and you need to be prepared when it does. Several years ago, a business had a state-of-the-art server room on the top floor of its building. The room was climate controlled and a true thing of beauty. Directly above the server room was the roof, and on the roof was the bank of air conditioners for the six-floor building. Over the course of one extremely hot weekend, the drain lines for the condensation from the air conditioners clogged. The lines filled with water and then burst, and the water came through the