The best practice for mitigating the risk of site destruction, denial, or unavailability causing disastrous loss of critical services is to deploy redundant systems in a geographically separated location; this practice is called geographic redundancy or georedundancy. Enterprises deploying a geographically redundant system may spend significantly more than when deploying a standalone configuration up front, and will have higher ongoing operating expenses to maintain the geographically separated redundant recovery site and system. While the business continuity benefits of georedundancy are easy to understand, the feasible and likely service availability benefits of georedundancy are not generally well understood. This book considers the high-level question of what service availability improvement is.
