sk1 001 server plus certification bible phần 7 pps

350 Part V ✦ Security Daily tasks Daily tasks should consist of trash removal, and the removal of any other items that should not be kept in the computer room. This may included cardboard boxes from newly unpacked equipment. Vacuuming may be required if the computer room is used as a print room, or if there are a lot of people moving through the room. Weekly tasks The access floor system should be maintained on a regular weekly basis. The access floor system is simply the type of flooring used in raised room computer environments. A typical raised floor system uses removable panels for access to network cabling, power cables, and so on. You want to ensure this area is clean because the air conditioning system uses it for air distribution. The access floor system should be vacuumed and damp mopped for a good thorough cleaning. All vacuums used in the computer room should be equipped with a HEPA filtration sys- tem. Equipment that is not properly filtered will cause small particles to escape the vacuum and drift into the server room environment where they may migrate to your hardware. Make sure that rags and mop-heads are designed not to shed. Use cleaning solutions that do not pose any kind of threat to the computer hard- ware. Potentially damaging solutions include phosphate products, bleach products, chlorine products, ammonia products, petro-chemical products, floor strippers, and reconditioners. Use the exact recommended mixtures for cleaning, because over-strengthening the mixture can cause problems. Quarterly tasks Only professional computer room cleaning agencies should do the cleaning during this phase of the schedule. This type of cleaning should be done at least three to four times per year depending on the amount of traffic in the server room. All sur- faces should be thoroughly cleaned, including racks, shelves, equipment, cup- boards, and ledges. Ensure that any high ledges and light fixtures that attract large amounts of contaminants get cleaned thoroughly. If there are any windows, ensure they are thoroughly cleaned. Any doors or glass partitions should also be treated in this phase. Settled contaminants should be cleaned from all exterior hardware sur- faces. The computer’s air intake and exhaust grilles should be cleaned as well. Using wipes for this type of cleaning is not recommended; a low powered source of compressed air is more suited for this type of cleaning. Keyboards, and other input devices should also be cleaned. Monitors should be cleaned with optical cleansers and static-free wipes or cloths. Be sure that the company uses appropriate cleaning materials. There are special dust cloths treated with particle absorbent materials that are specially designed for this type of application. Biannual tasks Based on the condition of the plenum surfaces, and the amount contaminate buildup, the sub-floor area should be cleaned every 18 to 24 months. Even if you perform the weekly cleaning duties, which reduce much of the contamination, some of the dirt will find its way into the sub-floor area. Because the sub-floor is a source 4809-3 ch14.F 5/15/01 9:49 AM Page 350 351 Chapter 14 ✦ Environmental Issues for your hardware’s air supply plenum in a raised-floor environment, you need to keep this area extremely clean. The people who perform this type of cleaning should have a complete understanding of the process to ensure they can properly assess cable connectivity and priority. All sub-floor activities need to be conducted with proper consideration for the air distribution system and floor loading. The number of tiles that are removed from the floor must be carefully managed in order to ensure the integrity of the access floor. Typically, no more than 24 square feet of tiles should be removed from the flooring at any one time. The access floor’s sup- porting grid system should also be thoroughly cleaned with a vacuum, and then with a damp sponge. Note and report any odd conditions, such as damaged floor suspension, floor tiles, cables, and surfaces within the floor void. Electrical Issues ✦ Recognize and report on server room environmental issues (temperature, humidity/ESD/power surges, back-up generator/fire suppression/flood considerations) To prevent failures, the power system must be designed to ensure that adequate power is provided to the computer hardware. All power should be distributed from dedicated electrical distribution panels. If computer equipment is subjected to repeated significant power interruptions and fluctuations, components may fail. Quality of power source Power quality issues can often be difficult to identify, and are usually even more dif- ficult to fix. The symptoms are often confused with hardware or software problems. The only way to ensure proper power quality is through proper design of the sys- tem. A vital part of the system design is to ensure adequate redundancy, and elimi- nate single points of failure. The following areas should be addressed in the design of the power systems for a computer room. Multiple feeds Multiple utility feeds should be provided from separate substations or power grids. This is not essential, but it provides backup and redundancy to the system. The importance of the data on your servers dictates the importance of multiple power feeds. UPS A UPS should be installed to carry the full load of the computer hardware for a period that is at least long enough to transfer the equipment to an alternate utility feed or backup generator. The UPS should also be able to accommodate 150 per- cent of the load for fault overload conditions. Use an on-line UPS that runs continu- ously as opposed to an off-line unit. Battery backup should be capable of providing at least 15 minutes of power to maintain the critical load of the room, and to allow adequate time to transfer power to a generator. Objective 4809-3 ch14.F 5/15/01 9:49 AM Page 351 352 Part V ✦ Security Uninterruptible power supplies are discussed in more detail in Chapters 2 and 10. Backup generators Depending on how critical it is to ensure power even during a power failure, you may be able to use a UPS and multiple utility feeds without backup generators. If you decide to use a backup generator, it should be able to carry the fully load of the computer equipment, as well as all the support equipment like air conditioners and lighting. Maintenance bypass The power system design should have the ability to bypass and isolate any point of the system so that a technician can perform maintenance, repair, or modifications without interrupting normal system operations. The system must be designed to avoid all single points of failure. Proper grounding Proper grounding is essential for all electronic equipment. Grounding design in a computer room environment must address both the electrical service as well as the equipment. Grounding design should comply with your local electrical codes. A properly designed grounding system should have as low an impedance as is practi- cally achievable for the electronics as well as for safety. Impedance is a material’s opposition to the flow electric current, and it is measured in ohms. The ground should be continuous from the central grounding point at the origin of the building system. Electronic equipment can be sensitive to stray currents and electronic noise. Therefore, you need to have a continuous, dedicated ground for the entire power system to avoid a ground differential between various grounds. All metallic objects that contain electrical conductors or those that are likely to be charged by electrical currents, such as lightning or electrostatic discharge, should be effec- tively grounded. This will ensure personnel safety, fire reduction, and protection of the equipment. The common point of ground can be connected to any number of sources at the service entrance: water piping, building steel, or even a driven earth rod. It is recommended that the central point of grounding at the service entrance should be connected to multiple ground sources to ensure redundancy in the event that any one source should become unreliable, for example, if a water pipe bursts. Electrostatic discharge Electrostatic discharge (ESD) is perhaps the most common power problem you will encounter. Static can strike anywhere, and at any time. ESD typically does not pose a personal safety threat, but servers can be severally damaged. Electrostatic dis- charge easily exceeds the acceptable limits of system operation. Even though the discharge lasts no longer than two or three nanoseconds, it is long enough to destroy sensitive circuits. ESD comes from any number of sources: humidity, car- peting, air vents, clothing, office furnishings, and altitude. Anything that moves can Cross- Reference 4809-3 ch14.F 5/15/01 9:49 AM Page 352 353 Chapter 14 ✦ Environmental Issues generate an electrical field. Simply walking past equipment, or even air movement, can cause ESD. Climate and geographic location play a big factor in static. At sea level in a warm climate, with normal humidity, you may not see much ESD. However, if you are in a high-rise office building, with strong controls determining the air quality, you will most likely see high amounts of static. Follow these precautions to minimize possible ESD induced failures in the computer room: ✦ Maintain the recommended humidity level and airflow rates in the server room. ✦ Use conductive wax if waxed floors are used. ✦ Use appropriate furniture in the server room that will significantly decrease the chance of ESD because the movement of inappropriate furniture can cause static discharges. ✦ Store spare electronic equipment in antistatic containers. ✦ Install conductive flooring, and be sure a conductive adhesive is used during installation. ✦ Ensure that all equipment and flooring is properly grounded and are con- nected to the same ground source. ✦ Always use a grounded wrist strap or other method (touching a grounded metal chassis) when handling circuit boards. Fire Safety 5.2 Recognize and report on server room environmental issues (temperature, humidity/ESD/power surges, back-up generator/fire suppression/flood considerations) A fire in the server room can have catastrophic effects on the operations of the room and the company. The destructive force of a full-fledged fire can damage electronic equipment and even the building structure beyond repair. The contaminants intro- duced from a smoldering fire can also damage hardware, and will most likely incur heavy cosmetic costs. Even when a fire is avoided with fire suppression equipment, this too can severally damage the computer hardware. Any sort of fire can have a staggering cost. You must keep off-site backups to ensure a quicker recovery of the computer systems, and a quicker return to regular business operations. Fire extinguishers Install manual pull stations at strategic points in the server room. Manual pull sta- tions will activate the fire suppression discharge equipment. If gas is used, there should be a means of manual abort for the suppression system as well. Place portable fire extinguishers throughout the room. These should be unobstructed, Objective 4809-3 ch14.F 5/15/01 9:49 AM Page 353 354 and should be clearly marked. Labels should be visible above tall pieces of equip- ment from anywhere in the room. Appropriate tile lifters should be located at each extinguisher station to provide access to the sub floor void for inspection, or to put out a fire. Sprinkler systems A passive suppression system reacts to detected hazards with no manual interven- tion. The most common forms of passive suppression are sprinkler systems or chemical suppression systems. Sprinkler systems can be flooded (wet pipe) or pre- action (dry pipe). A flooded system uses pipes that are full at all times, enabling the system to discharge immediately upon the detection of a fire. A pre-action system floods the sprinkler pipes upon the initial detection, but has a delay before actual discharge of the fire suppressant. The advantage of a pre-action system is that there is no risk of a pipe bursting and flooding the room with water. Non-liquid systems Chemical total flooding systems work by suffocating the fire within the controlled area. The suppression chemical most often found in server rooms is Halon 1301, but this is being eliminated in favor of the more environmentally friendly FM200 or various forms of water suppression. Carbon dioxide systems are also used, but can be a major concern because of operator safety in the event of a discharge. Carbon dioxide is a colorless, heavy gas used for extinguishing flames, but is deadly if breathed in. These systems can be used independently or in combination depend- ing on the exposures in the room. The ideal system incorporates both a gas system and a pre-action water sprinkler system in the computer room. Gas-suppression systems are better for the hardware in the event of discharge, because hardware can typically be brought back on-line as soon as the room is cleared of the gas. Unfortunately, gas systems are a one-time deal. If a fire is not put out by the discharge, there is no second chance. The gas system cannot be used again until it is recharged. Water systems can continue to address the problem until the fire is brought under control, but often cause irreparable damage to the hardware. Building owners, local laws, and insurance companies often require water suppression systems. Floods 5.2 Recognize and report on server room environmental issues (temperature, humidity/ESD/power surges, back-up generator/fire suppression/flood considerations) Objective Part V ✦ Security 354 4809-3 ch14.F 5/15/01 9:49 AM Page 354 355 Chapter 14 ✦ Environmental Issues In recent years, company IT systems have been hit by the worst floods in decades. The companies whose building were flooded had to face the decision of moving back to the damaged building or relocating. Many companies choose to relocate because they do not want to go through the process of trying to rebuild the IT infrastructure again. Most floods in the computer room are caused by leakage from the cold water pipes in the air conditioning systems. Another common source of flood water is pipes running through the ceiling void above the computer room. Leaks from roofs, espe- cially during a snow melt, are also a big problem where the computer room is in a single-story flat-roofed building. Computer systems in building basements are also at high risk because they are at the lowest point of the building and water always finds the lowest point. The biggest problem with detecting flood water early is that you do not know where the water ingress will start. However, there are hardware packages that can be pur- chased to assist in early flood detection. These systems are capable of detecting water at multiple points in the server room. You place as many of these detectors as you want at different areas in the server room. One obvious place to place the detectors is under every air conditioner that is in the room, and near or under criti- cal computer equipment. There are a few things that you can do regarding the construction of the computer room to protect against floods. Make sure the computer room is higher up in the building and not in a vulnerable basement. You should also ensure that your com- puter room uses raised flooring so that all critical equipment is off the ground. Key Point Summary This chapter focused on the important issues concerning environmental issues in the server room. This chapter represents a very small portion of the goals of the Server+ exam objectives, but it does not mean that it is any less important. A suc- cessful administrator must know that environmental issues plague the computer room environment. Keep the following points in mind for the exam: ✦ Electronic equipment have two sets of acceptable temperature ranges: Power off or cold temperature range, and the operating temperature of the equipment ✦ High humidity levels can cause resistance between connections in compo- nents, and low humidity levels cause high static buildup ✦ Ventilation is required in computer rooms to introduce a minimal amount of fresh air for operator safety, due to the nature of recirculating air conditioning systems 4809-3 ch14.F 5/15/01 9:49 AM Page 355 ✦ The cooling capacity of the air conditioning equipment must counter the heat dissipation of the computer equipment ✦ Controlling pollutants in the computer room is important when looking at the computer room environment ✦ Contaminants in the computer room come from many different sources ✦ Filtration systems help to effectively control contaminants in the computer room ✦ Computer rooms must be cleaned regularly to control contaminants ✦ The design of the power system must ensure that adequate power is provided to the computer hardware ✦ Fire suppression systems and equipment such as fire extinguishers, and a sprinkler system must be used to help limit the devastating affects of a fire ✦✦✦ 356 Part V ✦ Security 4809-3 ch14.F 5/15/01 9:49 AM Page 356 357 STUDY GUIDE The Study Guide section provides you with the opportunity to test your knowledge about hazardous environmental conditions in the server room. The Assessment Questions provide practice for the test, and the Scenarios provide practice with real situations. If you get any questions wrong, use the answers to determine the part of the chapter you should review before continuing. Assessment Questions 1. A new server has just been delivered to the computer room. The warehouse personnel mentions that it sat in the loading dock for over an hour in 32- degree temperatures. What should you do? A. Fire it up immediately. B. Wait for the equipment to reach the server room temperature. C. Point a space heater at the server to warm it up. D. Turn the air conditioner down to cool the room temperature. 2. You notice that the humidity level is low in the computer room. What might result because of this? A. ESP B. EDI C. ESD D. Nothing 3. Upon close inspection of the computer room, you notice small gaps around the doorway. What will prevent contaminants from entering through these gaps? A. Positive attitude B. Silicone C. Putting in a new entrance D. Positive pressurization 357 Chapter 14 ✦ Study Guide 4809-3 ch14.F 5/15/01 9:49 AM Page 357 4. What factors should be considered regarding an air conditioning system? Choose all that apply. A. Continuous operation for 24 hours and 365 days per year B. Independent of other systems in the building C. Accommodate expansion D. Allow outside air in to the room to accommodate human occupants, and to maintain positive pressurization E. All of the above 5. Your boss is looking at replacing the old air conditioning system with a newer one. She would like to know what the best system would be. What would you recommend? A. A central station air handling unit B. A complete self-contained package unit with remote condensers C. A window-mounted air conditioner D. A chilled water package unit 6. Contaminants come in many forms, however, some of the most harmful ones are not visible to the naked eye. How small are they? A. Less than 10 microns B. 1000 microns C. 0.3 microns D. 100 microns 7. What are the two criteria that must be met in order for a contaminant to be considered harmful? A. They must have physical properties that could cause damage to equip- ment, and they must remain stationary. B. They must have physical properties that could cause damage to equip- ment, and they must have the ability to travel to areas where they can cause damage. C. They must have the ability to travel to areas where they can cause dam- age, and they must not have any physical properties. D. None of the above. 358 Chapter 14 ✦ Study Guide 358 4809-3 ch14.F 5/15/01 9:49 AM Page 358 359 8. Your boss asks you to come up with a cleaning schedule for the server room. What should it incorporate? A. Daily and yearly tasks B. Daily, weekly, and quarterly tasks C. Weekly, quarterly, and semi-annual tasks D. Daily, weekly, quarterly, and bi-annual tasks 9. What areas should be addressed in the design of a power system? A. Multiple feeds, UPS, backup generators, maintenance bypass B. Multiple feeds, backup generators, maintenance bypass C. Multiple feeds, UPS, backup generators D. Multiple feeds, UPS, maintenance bypass 10. To help prevent ESD when working on a server, what precautions can you take? Choose all that apply. A. Wear a grounded wrist strap. B. Maintain proper humidity levels. C. Wear a wool shirt, and polyester pants. D. Use conductive furniture. Scenarios 1. Management wants you to come up with the best possible solution for a fire prevention system to protect the mission-critical systems in the computer room. What would you recommend? Answers to Chapter Questions Chapter pre-test 1. Computer systems have an ideal operating temperature range. Temperatures above or below this range can have serious side effects. 2. The standard temperature range is between 70 and 74 degrees F. 3. High humidity levels can cause resistance between connections, and low humidity levels can cause ESD. 359 Chapter 14 ✦ Study Guide 4809-3 ch14.F 5/15/01 9:49 AM Page 359 [...]... of the top causes of disk failure is excessive vibration Checking server components Open the server cases up and inspect them for excessive contamination (dust or other particles) If you notice a lot of contamination, clean it immediately You 4809-3 ch15.F 5/15/01 9:49 AM Page 377 Chapter 15 ✦ Determining the Problem should then get the server room decontaminated, and have a technician check the air... troubleshooting methodology This methodology has six key steps: 1 Keep the servers up to date 2 Eliminate the obvious 3 Gather information about the problem 4 Simplify 5 Perform testing 6 Document what solved the problem 3 67 4809-3 ch15.F 368 5/15/01 9:49 AM Page 368 Part VI ✦ Troubleshooting Keep the servers up to date A large majority of problems with servers have already been resolved by the vendor and are available... map as well The server inventory should include the location of the server, make, model, serial number, operating system, memory, network cards, and any other peripheral devices It should also detail the purpose of the server (application, database, print, and so on) I recommend that you use a third-party program for this purpose, as they are very good at discovering what is on the server, including... ✦ Cables (power cords, serial cables, network cables, and so on) ✦ Concentrators and hubs (perhaps routers, depending on how critical the service is) 371 4809-3 ch15.F 372 5/15/01 9:49 AM Page 372 Part VI ✦ Troubleshooting If a network card fails in a server, you have the exact spare in your inventory, which makes the problem easy to fix Your users would be back to work in no time at all However, if... lights that should be on? ✦ Are there any messages on server screens from event monitors? ✦ Do you see smoke? ✦ Do you notice a lot of dust or other contaminants? ✦ Are there any trash cans that should not be in the server room, or other garbage lying around? Sound Most server rooms have lots of loud noises from air conditioners, cooling fans in servers, and the other equipment in the room Thus, noise... should listen for when you enter a server room: ✦ Are any fans especially noisy, or are there any that don’t sound right? ✦ Are any noises not present that are normally there (cooling fan stopped, air conditioner stopped)? ✦ Are hard drives making unusual noises? ✦ When users dial in, are the modems picking up correctly? 375 4809-3 ch15.F 376 5/15/01 9:49 AM Page 376 Part VI ✦ Troubleshooting Smell... problem? 7 What are indicator lights on servers or devices? 8 Why should you check cabling? 9 Why should you check software problems first? 10 In a multi-level support system, what would a Level 1 support technician be responsible for? ✦ Answers to these questions can be found at the end of the chapter ✦ 4809-3 ch15.F 5/15/01 9:49 AM Page 3 67 Chapter 15 ✦ Determining the Problem I solating the cause of a server. .. External drives All of these devices have indicator lights on them, and if something is wrong, the unit is designed to manipulate the lights in a pattern that you can look up in the 377 4809-3 ch15.F 378 5/15/01 9:49 AM Page 378 Part VI ✦ Troubleshooting hardware manual It may be as simple as a loose connection, or as complex as a fried component The key to troubleshooting when it comes to hardware is... show the overall health of your servers, and network Health logs will help you to find specific patterns on your servers before they become big problems These logs will show a trend or pattern over the course of the time period that the log was capturing information The following items are typically monitored in health logs: ✦ Allocated server processes ✦ Available server processes ✦ CPU utilization... your servers every night, once a week, and so on Depending on the availability of your servers, you may be able to set up a schedule to scan the servers every night A good example would be to setup the scan job to take place between 9:00 p.m and 12:00 a.m This time period may be when the least amount of people are on the network , and prior to the backup jobs that start at midnight Many of the server . problem Objective 4809-3 ch15.F 5/15/01 9:49 AM Page 3 67 368 Part VI ✦ Troubleshooting Keep the servers up to date A large majority of problems with servers have already been resolved by the ven- dor. Recognize and report on server room environmental issues (temperature, humidity/ESD/power surges, back-up generator/fire suppression/flood considerations) A fire in the server room can have catastrophic. capable of detecting water at multiple points in the server room. You place as many of these detectors as you want at different areas in the server room. One obvious place to place the detectors