Disaster recovery

Disaster recovery (DR) involves a set of policies and procedures to enable the recovery or continuation of vital technology infrastructure and systems following a natural or human-induced disaster. Disaster recovery focuses on the IT or technology systems supporting critical business functions, as opposed to business continuity, which involves keeping all essential aspects of a business functioning despite significant disruptive events. Disaster recovery is therefore a subset of business continuity.

Disaster recovery developed in the mid- to late 1970s as computer center managers began to recognize the dependence of their organizations on their computer systems. At that time, most systems were batch-oriented mainframes which in many cases could be down for a number of days before significant damage would be done to the organization.

As awareness of the potential business disruption that would follow an IT-related disaster, the disaster recovery industry developed to provide backup computer centers, with Sun Information Systems (which later became Sungard Availability Services) becoming the first major US commercial hot site vendor, established in 1978 in Philadelphia.

During the 1980s and 90s, customer awareness and industry both grew rapidly, driven by the advent of open systems and real-time processing which increased the dependence of organizations on their IT systems. Regulations mandating business continuity and disaster recovery plans for organizations in various sectors of the economy, imposed by the authorities and by business partners, increased the demand and led to the availability of commercial disaster recovery services, including mobile data centers delivered to a suitable recovery location by truck.

With the rapid growth of the Internet through the late 1990s and into the 2000s, organizations of all sizes became further dependent on the continuous availability of their IT systems, with some organizations setting objectives of 2, 3, 4 or 5 nines (99.999%) availability of critical systems. This increasing dependence on IT systems, as well as increased awareness from large-scale disasters such as tsunami, earthquake, flood, and volcanic eruption, spawned disaster recovery-related products and services, ranging from high-availability solutions to hot-site facilities. Improved networking meant critical IT services could be served remotely, hence on-site recovery became less important.

...
Wikipedia