Disaster Recovery Strategies

The following are the commonly followed strategies in the increasing order of Recovery Time Objective (Time is taken to restore once disaster strikes) and cost.

1. Backup and Restore – Complete offline. High recovery time and data loss. Less expensive.
2. Pilot light strategy – Bare minimum mechanism in place to get the system back as early as possible. For example, in the case of a database, there could be a read replica. Application / Web servers are set up post the disaster. Comparatively less recovery time and data loss. Comparatively expensive.
3. Warm mode – Completely production replica in place but it doesn’t serve the traffic. Minimum downtime. Less recovery time and data loss. Expensive.
4. Active mode – Replica setup as above but serves traffic. No downtime and data loss. Very expensive setup.