Disaster Recovery Strategies and Solutions
What the exam tests
Strategy questions require selecting recovery solutions that meet approved RTO/RPO targets at justified cost, covering data, applications, infrastructure, people, facilities, and suppliers.
Core rules
- Match options to tiers: backup and restore for long RTO; warm standby, replication, or pilot light for moderate RTO; active-active or high availability for short RTO and RPO.
- Alternate sites range from cold to warm to hot. Cloud multi-zone and multi-region designs are options, but you still own recovery testing and data protection.
- Backups need the 3-2-1 pattern, immutable or offline copies to resist ransomware, encryption, and restore testing. Replication is not a substitute for backup.
- Define recovery sequencing and dependencies: identity, network, data, application, interfaces, then business operations.
- Include people, workspace, communications, and supplier workarounds; contracts should specify recovery commitments and evidence.
Worked example
A Tier 1 service needs RTO 1 hour and RPO 5 minutes. A nightly backup cannot meet either objective. The chosen design is active-active across availability zones with synchronous replication, plus cross-region backup for corruption or region loss. A Tier 2 reporting service with RTO 24 hours uses backup and restore. Reasoning: spend follows business impact; the Tier 1 design addresses both availability and data loss, while the Tier 2 design is cheaper and adequate.
Traps
Buying a hot site for every system; assuming the cloud provider’s DR covers application data; treating replication as backup; never testing restore; and ignoring communications, staff, and supplier dependencies.