Disaster recovery plan (DR) is defined as (1) The use of alternative network circuits to re-establish communications channels in the event that the primary channels are disconnected or malfunctioning, and (2) The methods and procedures for returning a data center to full operation after a catastrophic interruption (e.g., including recovery of lost data).
Disaster recovery is a process, not so much a product—although many vendors will identify their offerings as DR solutions or tools. Disasters are inevitable, given enough time; whether a company engages in a successful disaster-recovery effort depends primarily on how much planning it has invested in. Those companies that plan ahead for disasters—which may involve purchasing and implementing some sort of DR system or systems—are more likely to quickly return their business to normal operating status.
In the context of the data center, disasters can involve any number of natural or manmade events, ranging from utility outages (power and/or water), flooding, earthquakes, hurricanes, tornadoes, terrorist attacks and so on. A disaster-recovery plan must take into consideration the most likely disaster scenarios and prepare accordingly, but in an economical way that fits the company’s budget. Disaster recovery may involve temporary use of a remote data center site that is maintained for just such a purpose, or it may involve relocation of operations at one facility to one or more standard facilities, if the company maintains more than one. Data backup is a critical part of a DR effort: if data is maintained in a single location and the containing media are damaged or destroyed in a disaster, that data could be lost forever. By storing copies of data elsewhere, the chances of losing that data in a disaster are greatly mitigated.
More broadly, any company that must stop or curtail business operations because of a disaster can quickly lose large amounts of money—not to mention reputation, if it fails to return to normal operations in a timely manner. Many businesses, in fact, don’t reopen after a disaster, usually owing to a failure to plan sufficiently. Thus, given that disasters can strike anywhere at any time, disaster recovery—particularly the planning part—is something that companies (especially those operating data centers) must be able to implement at need.