To determine the correct PowerOne technology configuration for the required business outcome, we first need to determine the required business continuity requirements for a given cluster in terms of the following:
The architecture design process entails:
It is typical for an organization to classify its recovery needs on a per-application basis, resulting in collections of applications that have common availability requirements. This maps well to the PowerOne approach in which the cluster is the primary unit of consumption for a business. At the cluster level, one cluster could have an RPO and RTO that is different from that of another cluster, allowing a direct mapping of the recovery needs of applications to the clusters in which they run.
Here are examples of differing business continuity requirements:
Example 1: An organization requires continuous availability for a set of business-critical applications, without which they would no longer have a business. This means that no downtime is tolerated in a disaster situation and no data must be lost. RTO must be as close to 0 as physically possible, and RPO is also 0, meaning that no data can be lost.
Example 2: The same organization may also have a set of applications for which recovery time might be an entire day, and losing up to eight hours of data could be acceptable. This would indicate an RTO of 24 hours (minus estimates of how long it would take to roll forward), and an RPO of 8 hours.
Example 3: The same organization also has applications that are only used at month’s end, but they are business-critical at month’s end. This would mean that the closer to the end of the month a disaster occurs, the more rapid the recovery would need to be, including making the data set current. This will involve a detailed conversation to determine whether:
Investment in business continuity is the starting point; having confidence that your plan will work and save your business is critical. Confidence comes from regular testing, which must be non-disruptive, or at best minimally so, and performed in a controlled manner.
PowerOne makes possible these various business outcomes by making the right set of components and other resources available. This means that the initial sizing work must include understanding the business continuity requirements and how they will be implemented. This will help ensure that the components and configurations needed to fulfill the requirements are incorporated in the system definition and the correct technologies and capacities are available at implementation.