Planning your high availability solution
Before configuring an i5/OS high-availability solution, proper planning is necessary to ensure all the requirements for the solution have been met.
Each high availability technology has minimum requirements that should be met before configuring a specific solution. In addition to these requirements, it is important to also determine which resources should be made resilient. These resources, such as applications, data, and devices, should be evaluated to determine whether they should be highly available. If they require high availability, it is important to make any necessary changes to the environment prior to configuring a solution for high availability. For example, you might have data that resides in SYSBAS, which should be highly available. Before configuring a solution, you should move that data to an independent disk pool. Applications might also require changes to enable high availability.
- Cluster applications
Application resilience is one of the key elements in a clustered environment. If you are planning to write and use highly available applications in your cluster you should be aware that these applications have specific availability specifications. - Planning data resiliency
Data resilience is the ability for data to be available to users or applications. You can achieve data resiliency by using
IBM i
cluster technology
with either switched disks, cross-site mirroring, or logical replication
technologies. - Planning environment resiliency
Environment resiliency ensures that your objects and attributes remain consistent among resources defined in the high-availability environment. You need to identity which resources require a consistent environment to function properly and create a cluster administrative domain that will ensure that these resource attributes remain consistent in your high availability solution. - Planning clusters
Before implementing a high-availability solution, you must ensure that you met all prerequisites for clusters. - Planning the FlashCopy feature
You can use the FlashCopy® feature as a means to reduce your backup window in i5/OS high availability environments that use the external storage units of the IBM® System Storage®. Before using the FlashCopy feature, ensure that the minimum requirements have been met. - Security planning for high availability
Prior to configuring your high-availability solution, you should reassess the current security strategies in your environment and make any appropriate changes to facilitate high availability.