Security+ topic 3.4
Resilience and Recovery
Resilience means staying available when something fails. High availability uses clustering and load balancing so one failed server does not take down a service. Redundant power uses a UPS for short outages and generators for long ones. Recovery sites range from hot (ready to run right away) to warm (some equipment) to cold (just space and power). Backups can be full, incremental, or differential, and copies should be kept offsite and tested. Snapshots, replication, and journaling help restore data quickly. Plans are tested with tabletop exercises, failover tests, and simulations.
| Site | Ready to run | Equipment | Cost |
|---|---|---|---|
| Hot | Minutes to hours | Everything, data kept in sync | Highest |
| Warm | Hours to days | Some hardware, older data | Medium |
| Cold | Days to weeks | Space and power only | Lowest |
Resilience and Recovery vocabulary
- Hot site: A fully equipped backup location that can take over almost immediately.
- Load balancing: Spreading work across several servers so none is overloaded and one can fail safely.
- UPS: An uninterruptible power supply: a battery that keeps equipment running during short outages.
- Tabletop exercise: A discussion-based walk-through of how a team would respond to a scenario.
Exam-style practice questions
Try each one, then open the answer. To save your progress, take this quiz in the interactive course.
1. A hospital needs a backup location that can take over almost immediately if its data center fails. Which of the following should it use?
- (A) A cold site
- (B) A warm site
- (C) A hot site
- (D) An offsite tape vault
Show answer
(C) A hot site A hot site is fully equipped and ready to run right away.
2. Which of the following keeps servers running for a few minutes during a power outage until a generator starts?
- (A) A UPS
- (B) A load balancer
- (C) A SIEM
- (D) A PDU without batteries
Show answer
(A) A UPS A UPS provides battery power for short outages.
3. Leaders meet in a conference room to talk through how they would respond to a ransomware attack, step by step, without touching any systems. Which of the following is this?
- (A) A failover test
- (B) A tabletop exercise
- (C) A penetration test
- (D) A parallel processing test
Show answer
(B) A tabletop exercise A discussion-based walk-through is a tabletop exercise.
4. Web traffic is spread across four servers so that if one fails, the others keep the site running. Which of the following is this?
- (A) Load balancing
- (B) Journaling
- (C) Tokenization
- (D) Sandboxing
Show answer
(A) Load balancing Load balancing spreads work and supports high availability.