CDCP Business Continuity and Disaster Recovery — Questions and Answers
Question 1: What does Recovery Time Objective (RTO) define in a data center disaster recovery plan?
- The maximum acceptable duration to restore normal operations after a disruption (Correct answer)
- The maximum acceptable amount of data that can be lost after a failure
- The minimum time required between scheduled maintenance windows
- The total time needed to complete a full data backup cycle
Correct answer: The maximum acceptable duration to restore normal operations after a disruption
RTO defines how long a business can tolerate a system being unavailable after a disruption. It sets the target time limit within which services must be restored. RPO (Recovery Point Objective) is the related metric that addresses acceptable data loss, not RTO.
Question 2: A data center has an RPO of 4 hours. What does this mean for its recovery strategy?
- Systems must be restored within 4 hours of a failure
- No more than 4 hours' worth of data may be lost in a disaster (Correct answer)
- Backups must be completed within a 4-hour maintenance window
- The facility must have 4 hours of generator fuel reserve
Correct answer: No more than 4 hours' worth of data may be lost in a disaster
Recovery Point Objective (RPO) defines the maximum acceptable amount of data loss measured in time. An RPO of 4 hours means backups or replication must occur at least every 4 hours so that no more than 4 hours of data is ever at risk of permanent loss.
Question 3: Which disaster recovery site type allows the fastest failover because it mirrors the production environment with live, synchronized data?
- Cold site
- Warm site
- Hot site (Correct answer)
- Mobile site
Correct answer: Hot site
A hot site is a fully operational duplicate of the primary data center with identical hardware, software, and continuously replicated data. Failover can occur in minutes. A warm site has hardware but requires data restoration. A cold site is just space and power with no pre-installed equipment.
Question 4: In a BC/DR context, what is the primary purpose of conducting a tabletop exercise?
- To physically test generator failover under load
- To simulate disaster scenarios through guided discussion without disrupting live systems (Correct answer)
- To measure actual RTO by triggering a planned outage
- To train staff on operating raised-floor cooling units
Correct answer: To simulate disaster scenarios through guided discussion without disrupting live systems
A tabletop exercise is a discussion-based session where key personnel walk through a simulated disaster scenario to identify gaps in plans and decision-making processes — without touching live infrastructure. It is lower cost and lower risk than a full failover test or simulation.
Question 5: Which metric measures the average time a component is expected to operate before failing?
- Mean Time To Repair (MTTR)
- Recovery Time Objective (RTO)
- Mean Time Between Failures (MTBF) (Correct answer)
- Recovery Point Objective (RPO)
Correct answer: Mean Time Between Failures (MTBF)
MTBF (Mean Time Between Failures) measures the average operational time between failures and is used to assess equipment reliability. MTTR measures how long it takes to repair a failed component. Both together inform availability calculations: Availability = MTBF / (MTBF + MTTR).
Question 6: A data center uses asynchronous replication to a secondary site 500 km away. Which BC/DR characteristic does this most directly impact?
- RTO, because synchronization lag increases restore time
- RPO, because replication lag means some recent data may not be at the secondary site (Correct answer)
- MTBF, because distance increases the chance of link failure
- PUE, because long-distance links consume additional power
Correct answer: RPO, because replication lag means some recent data may not be at the secondary site
Asynchronous replication introduces a lag between when data is written at the primary site and when it arrives at the secondary site. If a disaster occurs during this lag window, that data is lost — directly impacting RPO. Synchronous replication eliminates this lag but requires low-latency links.
CDCP Business Continuity and Disaster Recovery
What does Recovery Time Objective (RTO) define in a data center disaster recovery plan?