Question 287 - FC0-U61 discussion

Availability is the measure of how accessible a system or service is to its users. Availability can be affected by various factors, such as hardware failures, software bugs, network outages, natural disasters, human errors, and malicious attacks. To improve availability, organizations can use various methods, such as redundant equipment, disaster recovery sites, continuity plans, and scheduled maintenance. However, not all methods have the same cost-effectiveness.

Redundant equipment is the practice of having backup or spare components that can take over the function of a failed component. This can improve availability by reducing the impact of hardware failures, but it also increases the cost of purchasing, installing, and maintaining the extra equipment.

Disaster recovery site is a location where an organization can resume its operations after a major disruption, such as a fire, flood, or earthquake. This can improve availability by allowing the organization to continue providing its services in the event of a catastrophic event, but it also requires a significant investment in infrastructure, security, and data replication.

Continuity plan is a document that outlines the procedures and resources needed to restore normal operations after a disruption. This can improve availability by ensuring that the organization has a clear and consistent plan to follow in case of an emergency, but it also requires time and effort to develop, test, and update the plan.

Scheduled maintenance is the practice of performing regular checks and repairs on the system or service to prevent or fix potential issues. This can improve availability by reducing the likelihood and severity of failures, but it also requires planning, coordination, and downtime.

Among these methods, scheduled maintenance is the most cost-effective, because it does not require additional equipment, infrastructure, or data replication, and it can prevent or mitigate many common causes of unavailability. Scheduled maintenance can also help extend the lifespan and performance of the existing components, reducing the need for replacements or upgrades.

CompTIA IT Fundamentals (ITF+) Certification Guide, page 8

Service Availability: Calculations and Metrics, Five 9s, and Best Practices, section "What is Availability?"