Disaster recovery is the ability to resume complete IT operations within a specific amount of time or recovery time objective (RTO) and at a specific point in the IT process or recovery point objective (RPO). A shorter RTO indicates a quicker recovery time while a lower RPO indicates fewer transactions and information lost during the unplanned outage.
Who uses disaster recovery and why
Organizations protect against outages or information loss as a form of insurance. The cost of outages or data loss can be measured in monetary terms or as intangibles such as health and safety, market share, or reputation. Each organization has a unique risk tolerance, and it's common for different applications to have different requirements for RTO and RPO.
How disaster recovery works
Companies try to back up their data on a regular schedule such as once every 24 hours. At these times they create one or more duplicate or deduplicated copies of the primary data and write it to a new disk or to a tape.
For disaster recovery purposes, a backup copy needs to be transported or replicated offsite to ensure the data is safe in the event of a disaster.
Benefits of disaster recovery
A single point of failure is a risk of data loss or system unavailability. A single device, building, metropolitan area, power grid, flood zone, or hurricane zone all represent a single point of failure. Redundancy and the distance that spans those points of failure enables disaster recovery to keep businesses and agencies in operation regardless of the cause of the unplanned outage.