Deck 15 - Disaster Recovery

RPO

Recovery Point Objective: the maximum acceptable amount of data loss that a business can tolerate, measured in units of time

RTO

Recovery Time Objective: the maximum acceptable length of time a system, application, or service can remain offline after an unexpected disruption before the business impact becomes unacceptable.

RPO vs RTO (key exam distinction)

RPO measures the tolerable amount of data loss before a disaster; RTO measures the tolerable amount of downtime after a disaster before service is restored.

MTBF

Mean Time Between Failure: the average working time between unplanned breakdowns of a repairable system; a higher MTBF suggests greater reliability and stability.

MTTR

Mean Time to Repair: The average time required to repair a failed component or device and return it to normal operations; a lower MTTR indicates more efficient fault recovery.

Cold Site

The most affordable recovery site type, but takes the most time to recover; contains no equipment, connections, or data, requiring days to weeks to recover.

Warm Site

A recovery site more expensive than a cold site but offering faster recovery; contains some equipment and connections, but with out-of-date configurations and data sets, requiring hours to days to recover.

Hot Site

The most expensive recovery site type but offers the fastest recovery time; contains all equipment, connections, and recent configurations and data sets, requiring minutes to hours to recover.

Active-Active Configuration

A setup where both systems run simultaneously, distributing the load to maximize performance and availability.

Active-Passive Configuration

A setup where one system is operational while the other stands by, ready to take over if the primary system fails, ensuring continuity but with potential downtime during the switchover.

Disaster Recovery Testing

A critical component of disaster recovery planning that ensures recovery procedures are effective and up-to-date; regular testing helps organizations prepare for and manage potential disruptions.

Tabletop Exercises

Discussion-based sessions where team members walk through various disaster scenarios to evaluate the effectiveness of the disaster recovery plan, without activating actual resources.

Validation Tests

Tests that involve the actual execution of disaster recovery processes to verify that systems and data can be restored in accordance with recovery objectives.