EXIN CDCE flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

PUE

Power Usage Effectiveness equals total facility power divided by IT equipment power. A value of 1.0 is theoretical; lower is better and it is the most cited efficiency metric.

Tier IV topology

Uptime Institute classification requiring fault tolerance and continuous cooling, with all electrical and cooling paths independently maintainable without shutting down the IT load.

2N redundancy

A design in which two complete, independent capacity systems are installed, each able to carry the full load alone. Failure of either system leaves full capacity available.

N+1 redundancy

One additional component beyond the number needed to carry the load. If one unit fails, remaining units still support full IT demand, but maintenance may reduce margin.

Hot-aisle containment

Physical enclosure of the hot aisle so exhaust air returns directly to cooling units. It prevents hot exhaust from mixing with cold supply air and improves cooling efficiency.

ASHRAE TC 9.9 envelope

Recommended and allowable temperature and humidity ranges for IT equipment classes A1 to A4. It guides cooling setpoints and economizer use in data centre design.

Single-line diagram

A schematic showing electrical distribution from utility through transformers, UPS, switchgear and PDUs. It identifies transfer points and single points of failure in the design.

Clean-agent suppression

Fire suppression using gases such as FM-200 or Novec 1230 that extinguish fire without water damage. Design must consider occupied-space safety and cylinder room sizing.

Method of Procedure

A step-by-step document for a specific, often non-routine task, listing prerequisites, sequence, verification steps, rollback and responsible persons before execution.

Standard Operating Procedure

A documented routine for recurring operational tasks such as rounds, filter changes or tape handling. It ensures consistent execution and supports audit and training.

Emergency Operating Procedure

A predefined response script for failures such as UPS transfer or cooling loss, specifying immediate actions, escalation and communication to reduce recovery time.

MTTR

Mean Time To Repair is total repair time divided by the number of repairs. It measures maintainability and directly affects availability when combined with MTBF.

MTBF

Mean Time Between Failures is total operating time divided by the number of failures. It estimates reliability and feeds availability calculations for critical systems.

Change management

A controlled process requiring risk assessment, approval, scheduling, rollback plan and post-implementation review for any change to production infrastructure or configuration.

Load bank test

A test applying an artificial electrical load to a generator or UPS to verify capacity, fuel system and cooling under realistic conditions without relying on IT load.

Two-person rule

A control requiring two authorised persons to be present for critical switching or access, reducing error and fraud risk in high-consequence operations.

Capacity threshold trigger

A predefined utilisation level, often 80 percent, at which power, cooling, space or network capacity requires action such as expansion or load rebalancing.

ISO/IEC 22237

An international series covering data centre facilities and infrastructure, including general concepts, building construction, power, cooling, ICT, security and management.

ISO/IEC 27001

The international standard for information security management systems. Annex A includes physical and environmental security controls relevant to data centre operations.

EN 50600

The European standard for data centre facilities and infrastructure, defining availability and protection classes. It aligns closely with the ISO/IEC 22237 series.

TIA-942

A telecommunications infrastructure standard for data centres specifying cabling, topology and Rated-1 to Rated-4 availability levels for design and build.

Uptime Institute Tier

A commercial certification of data centre topology and operational sustainability. It is not a national or international standard and differs from ISO certification.

PCI DSS physical controls

Requirements for cardholder data environments including badge access, visitor logs, CCTV retention and annual review of physical security controls.

SOC 2 Type II

An independent attestation report covering a period and testing operating effectiveness of controls, unlike Type I which assesses design at a point in time.

NFPA 75

A US fire code standard for fire protection of information technology equipment and information technology spaces, covering detection, suppression and construction.

DCiE

Data Centre Infrastructure Efficiency is the reciprocal of PUE, expressed as a percentage. Higher is better and it represents IT share of total facility energy.

WUE

Water Usage Effectiveness equals annual water consumption in litres divided by IT energy in kWh. It quantifies cooling water intensity for sustainability reporting.

CUE

Carbon Usage Effectiveness equals total carbon dioxide emissions divided by IT energy in kWh. It combines energy efficiency with the carbon intensity of supply.

RTO

Recovery Time Objective is the maximum acceptable time to restore a service after disruption. It drives redundancy, failover design and staffing levels.

RPO

Recovery Point Objective is the maximum acceptable data loss measured in time. It determines replication frequency and backup strategy for critical workloads.

Availability formula

Availability equals MTBF divided by MTBF plus MTTR. Annual downtime minutes equal one minus availability, multiplied by 525,600 minutes per year.

Colocation contract terms

Key clauses cover power density per rack, cross-connect fees, SLA credits, maintenance windows, escalation paths, renewal pricing and exit or migration assistance.