Appendix B: Identifying Availability Requirements for a Failover Cluster
Applies To: Windows Server 2008
You can use the following list of questions to help you gather, define, and clarify the deployment goals for your failover cluster. For more information about planning for a failover cluster, see Identifying Your Failover Cluster Deployment Goals and Mapping Your Deployment Goals to a Failover Cluster Design.
When users are working on the tasks that are important to the organization's central purposes, what data (or other resources) do they need, and what applications or services do they need when working with that data?
As you review the data and applications that users need, do you have access to any current or previous Service Level Agreements or similar agreements that define service levels? Do you have data about the cost or effect of service delays or outages?
For the users and tasks most important to the organization, what defines a satisfactory level of service?
Are services needed 24 hours a day, 7 days a week, or are they on some other schedule (for example, 9:00 a.m. to 5:00 p.m. on weekdays)?
What are the normal variations in load over time?
What increments of downtime are significant (for example, five seconds, five minutes, an hour) during peak and non-peak hours?
Based on the answers to previous questions, which services or applications have clear requirements for high availability in your organization?
Do the services or applications that you are focusing on all have the same availability requirements, or are some of them less important than others?
How many servers are available for failover clustering, and what type of storage is available for use in the cluster or clusters?
Is having a disaster recovery option important to the organization?
Can some of the clustered servers be placed in a separate site to provide an option for disaster recovery if a serious problem develops at the main site?