The only way to know for sure that your disaster recovery plan will work is to test it. When disaster strikes, ensure that your plan isn't a dud with frequent testing
"With so much emphasis placed on building out a disaster recovery plan, organizations often forget that they need to assess even the most detailed plans to ensure that everything will work. Without a disaster recovery testing strategy, there is no guarantee that all of your planning will be worth it in the end," warns
"It's a common tale: An organization needs to plan what steps to take when a disaster -- of varying types, scopes and levels of impact -- strikes. Typically, an organization puts quite a bit of effort into conducting a business impact analysis and a risk assessment, and then creating the plan itself..."