Despite the importance of a highly available data center, and the extent to which organizations have attempted to make their data centers fault-tolerant, achieving 100% availability is impossible. However, the goal of maximizing availability remains. The spectacular wreckage of failed systems leaves some poignant lessons in its wake. This week’s resources contain a number of such “never again” scenariosáse studies of particularly memorable system failures, their causes, and (in many cases) the lapses in judgment or planning that made disaster recovery more difficult than should have been necessary.

Read at least four of the case studies and think about the circumstances that precipitated the events. As you read, note the recurring causes of system failure and the impacts they had on the company and its data.

Select the three most compelling or significant causes of system failure illustrated in the case studies you chose. Briefly describe each by summarizing its role in one of the case studies you read. Of the three causes you list, select one that you feel presents the most significant challenge to maintaining the availability of a data center and explain why.