Disaster Recovery Planning: Strategies and Site Options
Learn about disaster recovery strategies, alternate processing site options, and key considerations for CISA exam candidates.
Understanding Disaster Recovery Planning
Disaster Recovery Planning (DRP) focuses specifically on the recovery of IT systems, data, and infrastructure following a disruptive event. While business continuity planning addresses the broader continuation of business operations, DRP concentrates on the technical recovery of the IT environment. For IS auditors, DRP is a critical control area because the inability to recover IT systems in a timely manner can have cascading effects on all business operations.
Disaster Recovery Strategies
Organizations can choose from several recovery strategies based on their RTO and RPO requirements:
- Hot Site: A fully equipped facility with hardware, software, network connectivity, and current data. Hot sites can be activated within minutes to hours, supporting the most aggressive RTOs. They are the most expensive option but provide the fastest recovery.
- Warm Site: A facility with hardware and network infrastructure in place but without current data. Warm sites require data restoration from backups before they can be operational, typically supporting RTOs of 24 to 72 hours.
- Cold Site: A facility with basic infrastructure (power, cooling, network cabling) but no pre-installed hardware or data. Cold sites require significant setup time, supporting RTOs of days to weeks. They are the least expensive option.
- Mobile Site: A self-contained, transportable unit that can be deployed to a location near the disaster site. Mobile sites provide flexibility but may have limited capacity.
- Reciprocal Agreement: An arrangement between two organizations to provide backup processing facilities for each other. While cost-effective, reciprocal agreements carry risks related to capacity constraints and confidentiality.
Key DRP Components
A comprehensive disaster recovery plan should include:
- Recovery Procedures: Step-by-step instructions for restoring each critical system, including the sequence of recovery activities.
- Communication Plan: Procedures for notifying stakeholders, employees, customers, and regulators during and after a disaster.
- Roles and Responsibilities: Clear assignment of recovery tasks to specific individuals and teams, with alternates identified for key positions.
- Vendor Contact Information: Contact details for hardware vendors, software providers, telecommunications carriers, and other critical suppliers.
Audit Considerations
IS auditors should verify that the DRP is documented, current, and aligned with the BIA. Auditors should assess whether recovery strategies are appropriate for the defined RTOs and RPOs, whether the alternate site is adequately equipped, and whether the plan has been tested successfully. Contracts for alternate processing facilities should be reviewed for adequacy of terms.
CISA Exam Tips
For the CISA exam, know the characteristics, advantages, and disadvantages of each site type. Hot sites offer the fastest recovery but at the highest cost. Cold sites are the cheapest but have the longest recovery time. Reciprocal agreements are considered the least reliable option due to capacity and confidentiality concerns. Questions frequently test the relationship between site type and achievable RTO.