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8.3. Disaster Recovery
As a quick thought experiment, the next time you are in your data center, look around, and imagine for a moment that it is gone. And not just the computers. Imagine that the entire building no longer exists. Next, imagine that your job is to get as much of the work that was being done in the data center going in some fashion, some where, as soon as possible. What would you do?
By thinking about this, you have taken the first step of disaster recovery. Disaster recovery is the ability to recover from an event impacting the functioning of your organization's data center as quickly and completely as possible. The type of disaster may vary, but the end goal is always the same.
The steps involved in disaster recovery are numerous and wide-ranging. Here is a high-level overview of the process, along with key points to keep in mind.
8.3.1. Creating, Testing, and Implementing a Disaster Recovery Plan
A backup site is vital, but it is still useless without a disaster recovery plan. A disaster recovery plan dictates every facet of the disaster recovery process, including but not limited to:
- What events denote possible disasters
- What people in the organization have the authority to declare a disaster and thereby put the plan into effect
- The sequence of events necessary to prepare the backup site once a disaster has been declared
- The roles and responsibilities of all key personnel with respect to carrying out the plan
- An inventory of the necessary hardware and software required to restore production
- A schedule listing the personnel to staff the backup site, including a rotation schedule to support ongoing operations without burning out the disaster team members
- The sequence of events necessary to move operations from the backup site to the restored/new data center
Disaster recovery plans often fill multiple looseleaf binders. This level of detail is vital because in the event of an emergency, the plan may well be the only thing left from your previous data center (other than the last off-site backups, of course) to help you rebuild and restore operations.
While disaster recovery plans should be readily available at your workplace, copies should also be stored off-site. This way, a disaster that destroys your workplace will not take every copy of the disaster recovery plan with it. A good place to store a copy is your off-site backup storage location. If it does not violate your organization's security policies, copies may also be kept in key team members' homes, ready for instant use.
Such an important document deserves serious thought (and possibly professional assistance to create).
And once such an important document is created, the knowledge it contains must be tested periodically. Testing a disaster recovery plan entails going through the actual steps of the plan: going to the backup site and setting up the temporary data center, running applications remotely, and resuming normal operations after the "disaster" is over. Most tests do not attempt to perform 100% of the tasks in the plan; instead a representative system and application is selected to be relocated to the backup site, put into production for a period of time, and returned to normal operation at the end of the test.
Although it is an overused phrase, a disaster recovery plan must be a living document; as the data center changes, the plan must be updated to reflect those changes. In many ways, an out-of-date disaster recovery plan can be worse than no plan at all, so make it a point to have regular (quarterly, for example) reviews and updates of the plan.