Cluster node considerations
You must consider the requirements of the cluster as a total entity. Remember that the surviving node must add the workload of the failed node to its own workload. Consider these areas:
- Processor capacity
- Application requirements
- Anticipated growth requirements
- I/O slot requirements
Also consider the number of input/output expansion slots the models provide. The selected model must have enough slots to house the components required to remove single points of failure (SPOF) and provide the desired level of availability. A SPOF is defined as any single component in a cluster whose failure would cause a service to become unavailable to end users.