Exin CDCP Certified Data Centre Professional (CDCP) Exam Practice Test

The primary reason to install a monitoring system in the data centre is to notice abnormalities early so that actions can be taken to avoid disasters, according to the CDCP Preparation Guide1 and various web sources234. A monitoring system is a system that collects and analyzes data about the power, cooling, environmental, and security conditions in the data centre, and alerts the operators or managers about any issues or threats that may affect the performance, availability, or reliability of the data centre. A monitoring system can help to prevent or minimize the impact of disasters, such as power outages, fire, water damage, overheating, equipment failure, or cyberattacks, by providing timely and accurate information that enables fast and corrective action. A monitoring system can also help to improve the energy efficiency, capacity planning, and asset management of the data centre, by providing useful insights and trends that support informed decision making.

References:

1: CDCP Preparation Guide, page 21, section 2.3.5 2: Improving Data Center Management and Monitoring5, page 1, section 1 3: Guide to Data Center Monitoring6, page 1, section 1 4: Why Data Center Monitoring is Essential7, page 1, section 1

According to the EPI Data Centre Training Framework, EMF is a form of electromagnetic interference (EMI) that can disrupt or damage the normal operation of electronic devices, such as servers, network cables, and IT equipment1. High levels of EMF can be generated by power equipment, cell phones, microwaves, TV and radio signals, etc., and can cause data corruption, data loss, system malfunction, and crashes23. Therefore, EMF can cause data centre failures and affect the availability, performance, and security of the data centre. To prevent or mitigate EMF, data centres should follow the best practices for data centre design, layout, cabling, grounding, shielding, and testing14.

References: 1: EPI Data Centre Training Framework, Module 5: Power, Section 5.4.1: Electromagnetic Interference, Page 5-34 2: EMI in the Data Center: To Shield Or Not ToShield2 3: Electromagnetic Interference in Data Centers: Risks Involved and Its Impact on Information Security4 4: Data Center Electromagnetic Interference and Tier Standards1

The casters and feet under the rack are used to support the weight of the rack and its equipment, and to allow the rack to be moved if needed. However, the casters and feet should also be designed to avoid putting too much pressure on the floor tile, especially if the data centre uses a raised floor system. A too heavy point load on the floor tile can cause the tile to crack, deform, or collapse, which can damage the rack, the equipment, and the underlying infrastructure. To prevent this, the casters and feet should be larger, so that they can distribute the weight over a larger area and reduce the point load. The casters and feet should also be compatible with the floor type and the load rating of the floor tile.

References:

1: CDCP Preparation Guide, page 22, section 2.4.1.1 2: Raised Floor Design Considerations for Data Center3, page 1, section 1 4: [SOLVED] server rack on casters or feet5, page 1, section 1

According to the CDCP Preparation Guide1, magnetic fields of the type ‘H’ or ‘B’ are created when an electric current flows through a conductor, such as a wire or a coil. The magnetic field strength ‘H’ is proportional to the current ‘I’ and the number of turns ‘N’ of the coil, and inversely proportional to the length ‘l’ of the coil. The magnetic flux density ‘B’ is proportional to the magnetic field strength ‘H’ and the permeability ‘μ’ of the medium in which the magnetic field exists. The greater the current, the stronger the magnetic field and the magnetic flux density. The relationship between ‘H’, ‘B’, ‘I’, ‘N’, ‘l’, and ‘μ’ can be expressed by the following equations:

H = N I / l

B =μH

References:

1: CDCP Preparation Guide, page 23, section 2.4.2.1 2: Difference between B and H in magnetic fields?3, page 1, section 1 4: Magnetic field | Definition & Facts5, page 1, section 1

IP protection grades are a way of showing the effectiveness of electrical enclosures in blocking foreign bodies such as dust, moisture, liquids, and accidental contact. IP stands for Ingress Protection or International Protection, and it is defined by the international standard IEC 60529. IP ratings consist of the letters IP followed by two digits and an optional letter. The first digit indicates the level of protection the enclosure provides against access to hazardous parts and the ingress of solid foreign objects. The second digit indicates the level of protection the enclosure provides against the ingress of water or fluids. The higher the number, the better the level of protection. For example, IP65 means the enclosure is dust-tight and can withstand water jets from any direction. IP68 means the enclosure is dust-tight and can be submerged in water under specified conditions.

References: EPI Data Centre Training Framework, CDCP Preparation Guide, IP code - Wikipedia, [IP Ratings Explained | Ingress Protection Rating | IP Codes | Updated 2022]

Measuring “Business Values” begins first with budgeting and identifying the costs associated with the project. This includes understanding the economic impact of the project, such as the cost of labor, materials, and other resources. It is also important to evaluate the return on investment (ROI) of the project, which will help to determine its overall value. Additionally, it is important to consider the long-term impact of the project and its potential to add value to the business in the future.

Damaged brand perception is an example of an indirect cost because it is not directly related to a specific product or service, but rather to the overall reputation and image of the company. Damaged brand perception can result from various factors, such as poor quality, customer dissatisfaction, security breaches, or negative publicity. Damaged brandperception can affect the company’s ability to attract and retain customers, partners, and investors, and thus reduce its profitability and competitiveness.

References: EPI Data Centre Training Framework, Indirect Cost: Definition and Example, What Is Indirect Cost? Definition, Types and Examples.

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According to the EPI Data Centre Training Framework, an isolation transformer is a device that transfers electrical power from one circuit to another without changing the voltage or frequency, but providing galvanic isolation1. Galvanic isolation means that there is no direct electrical connection between the input and output circuits, which can prevent ground loops, reduce noise, and improve safety2. An isolation transformer can also provide voltage stepdown or stepup, create a local ground-bonded neutral, reduce harmonic currents, and provide taps for abnormal mains voltage3.

The location of the isolation transformer in relation to the ICT equipment depends on the purpose and design of the transformer. In general, the isolation transformer should be as close as possible to the ICT equipment, but taking into account potential EMF4. EMF is a form of electromagnetic interference (EMI) that can affect the performance and reliability of the ICT equipment5. The closer the isolation transformer is to the ICT equipment, the shorter the cable length and the lower the voltage drop and power loss4. However, the isolation transformer should also be far enough from the ICT equipment to avoid EMF, which can be reduced by using proper shielding, grounding, and spacing5.

The isolation transformer should not be installed as far away as possible to the ICT equipment, as option B suggests, because this would increase the cable length and the voltage drop and power loss4. The isolation transformer does not have to be installed within the power entry point of the building, as option C suggests, because this is not a requirement of the electrical code or regulation, and it may not be optimal for the data centre power system. The isolation transformer should not be installed within the rack in which the ICT equipment has been installed, as option D suggests, because this would increase the heat load and the noise level in the rack, and it may not fit in the rack space.

References: 1: EPI Data Centre Training Framework, Module 5: Power, Section 5.4.3: Isolation Transformers, Page 5-38 2: Guidelines for using isolation transformers in data center UPS systems - EEP1, Page 1 3: The Role of Isolation Transformers in Data Center UPS Systems2, Page 2 4: Data Center Transformer | Power Distribution - FGC Construction3, Page 1 5: EPI Data Centre Training Framework, Module 5: Power, Section 5.4.1: Electromagnetic Interference, Page 5-34 : Data centre transformers manufacturers - TMC Transformers4, Page 1 : The Role of Isolation Transformers in Data Center UPS Systems2, Page 25

Class D fires involve combustible metals or combustible metal alloys such as magnesium, sodium and potassium. These metals can react violently with water, air, or other chemicals, and require special extinguishing agents1

References: 1: EPI Data Centre Professional (CDCP®) Reference Materials, page 16.

Measuring business value is the process of assessing the benefits and costs of IT investments and initiatives in relation to the strategic objectives and priorities of the organization. One of the factors that can be used to measure business value is scalability, which is the ability of a system or component to handle increasing workloads or demands without compromising performance, quality, or functionality. Scalability is important for business value because it enables the organization to adapt to changing market conditions, customer expectations, and growth opportunities. Scalability can also reduce operational costs, increase efficiency, and improve customer satisfaction. Therefore, scalability is one of the factors that can be used in measuring business value.

References:

•EPI Data Centre Training Framework1

•EPI Data Centre Competence Framework2

•Measuring the Business Value of IT3

•How to Measure the Business Value with Effective Data Quality Governance

•7 Rules for Demonstrating the Business Value of IT

Back-up generators are essential for providing power to the data centre in case of a utility outage. However, back-up generators also generate a lot of heat, which needs to be dissipated by a cooling system. The cooling system may rely on water supply, either from the municipal network or from a dedicated tank. If the water supply fails, the cooling system may not function properly, leading to overheating and potential damage to the generators. This could compromise the reliability and availability of the data centre power supply and cause downtime or data loss.

References:

1: CDCP Preparation Guide, page 18, section 2.3.2 2: Data Center Generator Cooling Systems3, page 1, section 1 4: Data Center Cooling Systems5, page 1, section 1

According to the Raised Floor Installation Manual, the best practice for cutting holes in the raised floor tile is to draw a cross on the tile and when making a cut-out do not touch a line and avoid the corners1. This ensures that the structural integrity and load-bearing capacity of the tile are not compromised. Cutting holes anywhere, touching the line, or cutting the corners can weaken the tile and cause it to crack or collapse1. Additionally, the manual recommends using a drill press or a reciprocating saw with a metal or bi-metal cutting blade, and deburring all sharp edges1.

References: 1: Raised Floor Installation Manual, E. Recommended Cutting Tools, Page 1

According to the IBM document on temperature and humidity design criteria1, the temperature and humidity values indicated on the display of the computer room air conditioner unit are the values measured at the intake of the air conditioner. This is because the intake is where the air conditioner draws the air from the computer room and cools and dehumidifies it before sending it back to the computer room. The display shows the current conditions of the computer room air, which are used to adjust the cooling and dehumidifying operations of the air conditioner. The values measured at the exhaust (outlet) of the air conditioner are not displayed, as they are not relevant for the computer room environment. The values measured at the front of the rack of the aisle the air conditioner is situated are also not displayed, as they may vary depending on the distance and location of the rack. The average value between the intake and exhaust (outlet) of the air conditioner is not displayed, as it does not reflect the actual conditions of the computer room air or the air conditioner performance.

References: 1: Temperature and humidity design criteria - IBM

A physical infrastructure in a Data Center consists of racks, which are metal frames used to store and organize server and other IT equipment. The racks are usually arranged in rows and columns, and they can be used to hold servers, storage devices, and other pieces of IT equipment. The racks can also be used to organize cables and other components to ensure that the Data Center is kept organized and efficient.

Hot- or cold-aisle containment is a strategy to improve the cooling efficiency and reduce the energy consumption of data centers by isolating the hot exhaust air from the cold supply air. However, implementing this strategy in an existing computer room may create potential issues with the existing fire suppression system(s), such as:

•The containment barriers may interfere with the distribution and activation of the fire suppression agents, such as water, gas, or aerosol, and reduce their effectiveness in extinguishing a fire.

•The containment barriers may create pockets of high temperature and pressure that could damage the equipment or the containment structure itself in the event of a fire.

•The containment barriers may obstruct the access and visibility of the fire detection and alarm devices, such as smoke detectors, heat sensors, or manual call points, and delay the response time of the fire suppression system(s).

•The containment barriers may violate the local fire codes and regulations that specify the minimum clearance and ventilation requirements for the data center.

Therefore, when implementing hot- or cold-aisle containment in an existing computer room, it is important to consider the impact on the existing fire suppression system(s) and take appropriate measures to ensure the safety and compliance of the data center, such as:

•Consulting with the fire authorities and the fire suppression system vendor to assess the compatibility and suitability of the containment solution with the existing fire suppression system(s).

•Modifying or upgrading the existing fire suppression system(s) to accommodate the containment solution, such as relocating or adding fire suppression devices, adjusting the discharge rate and pressure, or installing a secondary fire suppression system within the contained area.

•Installing fire-rated containment barriers that can withstand high temperatures and resist the spread of fire and smoke, and that have self-closing or automatic release mechanisms in case of a fire.

•Installing fire detection and alarm devices within the contained area and ensuring their proper integration and communication with the existing fire suppression system(s).

•Conducting regular testing and maintenance of the fire suppression system(s) and the containment solution to ensure their functionality and reliability.

References: EPI Data Centre Framework, Module 4: Fire Protection, page 10-11. EPI Data Centre Professional (CDCP®) Reference Materials, page 66-67. 1, 2, 3.

Optical fiber cables are composed of a core, a cladding, and a coating. The core is the central part of the fiber that carries the light signal. The cladding is the layer surrounding the core that reflects the light back into the core and prevents signal loss. The coating is the protective layer that covers the cladding and provides mechanical strength and environmental protection. The specifications of an optical fiber cable indicate the dimensions of the core and the cladding in microns (μm), which are one millionth of a meter. For example, a 50/125 μm cable has a core diameter of 50 μm and a cladding diameter of 125 μm. The coating diameter is usually 250 μm, but it is not part of the specifications.

References: Multimode Optical Fiber Selection & Specification - Corning, Optical Fiber OM3 (50/125µm Multimode Fiber), 50/125 Graded-Index OM2 Optical Fiber - OFS

Class C fires involve energized electrical equipment, such as computers, servers, switches, cables, and wiring. These fires require the use of non-conductive extinguishing agents, such as carbon dioxide, dry chemical, or clean agent, to prevent electrical shock and damage to the equipment. Water-based extinguishers, such as Class A or K, are not suitable for Class C fires, as water can conduct electricity and cause electrocution or short circuits.

References: EPI Data Centre Training Framework, CDCP Preparation Guide, ABCs of Fire Extinguishers

Shielded twisted pair cables (STP) are Ethernet cables that feature additional protection against electromagnetic interference from external sources, such as radio waves, microwaves, or other network cables. This is achieved by wrapping each pair of wires with a conductive shield, usually made of foil or braided wire, and then enclosing the entire cable with another shield layer. However, this shielding is not effective against low frequency electromagnetic fields (EMF) from power cables, which can induce currents and voltages in the network cables and cause signal distortion or data loss. Low frequency EMF can only be reduced by increasing the distance between the power and network cables, or by using a tre-foil cable arrangement, which is a special configuration of three power cables twisted together to cancel out the magnetic fields they generate.

References: STP Cable: Your Shield Against Network Disturbances; What is Shielded Twisted Pair Cable? - Advantages, Disadvantages; Shielded vs. Unshielded Cables: What’s the Difference? - Cable Matters.

According to the CDCP® Preparation Guide, an audible signaling and notification device is a device that produces a sound to alert or notify the occupants of a data center of an event or condition. Sirens are examples of such devices, as they can emit loud and distinctive tones to warn of fire, emergency, or security incidents. Strobes, on the other hand, are visual signaling and notification devices that produce flashes of light to attract attention or convey information. Alarms and clocks are not specific types of devices, but rather general terms that can refer to various audible or visual devices.

References: CDCP® Preparation Guide, page 30. Audible Visual Notification | System Sensor | Honeywell. Audible-Visual Signaling Devices - AutomationDirect.

The most damaging type of floor load for raised floor tiles in a data centre is the rolling load (RL), according to the CDCP Preparation Guide1 and various web sources234. A rolling load is the load that is applied by a moving object, such as a pallet jack, a forklift, or a rack on wheels. A rolling load can cause more stress and fatigue on the raised floor tiles than a static load, such as a concentrated load (CP) or a uniformly distributed load (UDL), because it creates dynamic forces and impacts that can crack, dent, or deform the tiles. Moreover, a rolling load can also damage the pedestals and stringers that support the tiles, and cause the tiles to become loose or misaligned. Therefore, when designing and installing a raised floor system, it is important to consider the maximum rolling load that the tiles can withstand, and to use appropriate materials and methods to enhance the strength and durability of the tiles. For example, some possible solutions include using steel or concrete-filled tiles, reinforcing the edges and corners of the tiles, and using locking or gravity-held systems to secure the tiles.

References:

1: CDCP Preparation Guide, page 23, section 2.4.2 2: Top 5 Considerations - Selecting a Data Center Raised Floor Tile5, page 1, section 1 3: Raised Floor Systems: Explained, Improved and Reinvented6, page 1, section 1 4: Raised Floor Systems: Common Problems and Solutions7, page 1, section 1

According to the IEEE definition, reliability is the ability of a system or component to perform its required functions under stated conditions for a specified period of time. Reliability is a measure of how often a system or component fails, and how long it takes to recover from a failure. Reliability is closely related to availability, which is the degree to which a system or component is operational and accessible when required for use. Reliability and availability are both affected by factors such as design, maintenance, testing, and environmental conditions.

References: EPI Data Centre Training Framework, CDCP Preparation Guide, Reliability engineering - Wikipedia