CompTIA Network+ (N10-009)Network OperationsHard
A company's disaster recovery plan requires a critical e-commerce application to be restored within 8 hours (RTO). The company is evaluating a cold site that requires 72 hours to procure, install, and configure replacement hardware before service can resume. Which conclusion is correct?
- AThe cold site exceeds the RTO requirement, meaning it recovers faster than necessary
- BThe cold site fails to meet the RTO requirement, so a warm or hot site should be considered instead
- CRTO and site tier selection are unrelated, so any site type is acceptable
- DThe cold site meets the RTO requirement because RTO refers only to data loss, not restoration time
Show answer & explanationAnswer & explanation
Correct answer: B. The cold site fails to meet the RTO requirement, so a warm or hot site should be considered instead
RTO defines the maximum acceptable time to restore service after a disruption. Since the cold site's 72-hour recovery time far exceeds the 8-hour RTO, it cannot satisfy the business requirement; a warm or hot site with pre-installed infrastructure would provide much faster recovery.
Why the other options are wrong
- A. This misreads the numbers; 72 hours is slower, not faster, than the 8-hour requirement.
- C. Site tier selection is directly driven by RTO requirements, making this false.
- D. RTO measures restoration time, not data loss (that's RPO), so this reasoning is incorrect.
RTO vs DR Site Tier Selection
Recovery Time Objective (RTO) is the maximum tolerable downtime after a disaster; the DR site tier chosen (cold, warm, hot) must be capable of meeting that RTO.
- Cold sites have longest recovery times (days)
- Warm sites recover in hours with partially configured systems
- Hot sites recover fastest (minutes to a couple hours) with fully mirrored systems
Memory trick: Cold is slow, Hot is quick — pick the site that fits the clock.