A disaster is any event that halts business activity on a large scale. In most cases, we are thinking about natural disasters, but there are also man-made disasters and all of them can happen at any time without warning. Technologies and all IT services could be impacted by these kinds of disasters. Of course, there are other and more important aspects; like human life that can also be at risk, but for BC, we put the main focus on the business-critical services and applications.
DR provides BC in the event of a disaster, and may be just localized on equipment (like a single server) or globally on an entire site. Business will be recovered by following a specific DR plan; it is just a subset of the BCP. In the worst case of a disaster that impacts an entire site or region, usually, the recovery process uses a remote location called a disaster recovery site.
DR is essential to ensure the continuation of business after a disaster. DR can also be required in several regulatory compliances. Effective DR is a critical part of a BCP that must address the following three organizational requirements:
- Minimize risks: Having a BC plan does not eliminate all risks if you cannot be certain that the plan is reliable or practicable. The DR plan could be difficult to implement, and for several organizations it may have some business impacts and possible risks.
- Minimize downtime: The consequences of extended downtime can be critical for business, recognition, and productivity. For most companies, a service disruption of ten or more days could be a total disaster and lead to the closing of the company itself.
- Control costs: Traditional disaster recovery plans are often limited in scope because of the cost, but you must find a tradeoff between the costs and risk mitigations.
Although everyone realizes the importance of a DR plan, some organizations do not have the proper level of DR protection that they need. Only after a real disaster does they fully understand the importance of DR and the real impact that a disaster can have on their business.
Legacy solutions and processes to activate applications in the DR site usually requires complex runbooks and manual procedures to execute the failover process. They may require highly specialized staff with vertical skills, large time investments, and high levels of coordination from several teams that are responsible for different layers of the infrastructure.
The main challenges that must be handled by DR, in order to have a successful and effective plan, are as follows:
- Complexity: Usually data center recovery plans are complex processes, because to guarantee the correct recovery of entire business services they must deal with all the interdependencies between applications, hosts, networks, and storage and other infrastructural and organizational aspects.
- Lack of predictable and reliable recovery: Recovery plans documented in run books can be incomplete and may quickly fall out of sync with rapidly evolving deployments. Most enterprises test their recovery plan only twice a year or less.
- High cost: Legacy DR solutions require significant capital and operating expenditures. The DR site typically requires a dedicated duplicate server infrastructure.
As defined in Gartner, Survey Analysis: IT Disaster Recovery Management Spending and Testing Activities Expand in 2012, July 2012: