5.6.5.3 Application Requirements
Policy design starts with an assessment of business needs and application requirements, because policies allow any configuration to become as customized as needed. Using general policies is advisable if no specific use cases exist, or if a proof of concept (PoC) is under development.
Start by assessing the following different application requirements:
• I/O performance and profile of your workloads on a per-virtual-disk basis
• Working sets of your workloads
• Hot-add of additional cache requires repopulation of cache
• Specific application best practice (such as block size)
Aim to design policies for availability and performance in a conservative manner, so that space consumed and recoverability properties are balanced. In many cases, the default system policy is adequate, and no additional policies are required, unless there are specific requirements for performance or availability.