Security and system resilience
The Resilience Plan
Continuity planning sets two clocks and a site: RTO is downtime tolerated, RPO is data loss tolerated, and the site speed must match.
How the exam words it
- -The stem defines a recovery objective and asks whether it is the RTO or the RPO, or how much downtime or data loss is acceptable.
- -It describes a recovery facility and asks whether it is a hot, warm, or cold site, or which fits a short RTO.
- -It contrasts backup strategies and asks which restore is fastest or which captures only changes, pointing to full, incremental, or differential.
- -It asks how business continuity planning relates to disaster recovery, or why recovery plans must be tested.
The playbook
- 1Separate the two objectives: RTO is the maximum tolerable downtime (time to restore), and RPO is the maximum tolerable data loss (age of the last usable backup).
- 2Match the site to the RTO: a hot site is fully equipped for near-instant failover, a cold site is just space and power, and a warm site sits in between.
- 3Compare backups: a full backup restores fastest from one set, incremental backs up only changes since the last backup (slow restore), and differential backs up changes since the last full.
- 4Treat disaster recovery as the IT subset of the broader business continuity plan, and insist the plan is tested regularly because an untested plan may fail when it is needed.
The trap
Swapping RTO and RPO, or pairing a long-downtime tolerance with a hot site. RTO is downtime, RPO is data loss, and a short RTO is what justifies a costly hot site.
How the exam varies it
The same pattern, re-skinned along these axes:
RTO versus RPO definitionHot, warm, or cold recovery site selectionFull, incremental, or differential backup, and BCP versus DRP scope
Drill this pattern
8 questions of The Resilience Plan from across the AUD topics. Clear it by getting 5 right with a streak of 3.