HP 3PAR Adaptive Optimization (AO) is a feature that enables autonomic storage tiering on HP 3PAR storage arrays. With this feature, the HP 3PAR storage system analyzes IO and migrates regions of 128 MB between different storage tiers. Frequently accessed regions of volumes are moved to higher tiers, while less frequently accessed regions are shifted to lower tiers. However, there are several misunderstandings and misconfigurations of AO that need to be addressed.

Firstly, it is important to note that physical disks are divided into 1 GB portions or chunklets. A Common Provisioning Group (CPG) creates a pool of logical disks (LD) and therefore a pool of storage, which can be provisioned to virtual machines (VMs). The fastest CPG should be configured as tier 0, while the slowest CPG should be configured as tier 2.

Secondly, AO requires at least two tiers to function correctly. It is recommended that three tiers be configured for optimal performance and cost balancing. The mode configuration parameter has three different options: “Performance,” which moves more data to faster tiers; “Cost,” which moves more data to slower tiers; and “Balanced,” which balances between performance and costs. Best practice is to use the “Balanced” mode as the default setting.

Thirdly, it is important to note that only AO moves data between storage tiers, so it is not necessary to schedule “compactcpg” to compact CPGs that belong to an AO config. Additionally, running AO every hour is not necessary, and it is sufficient to run it once a day during periods of low IO.

Lastly, it is important to avoid using automated techniques that move data between different storage tiers, such as VMware SDRS in fully-automated mode. However, these techniques can be used in manual mode and recommendations can be applied if necessary. By understanding these topics and best practices, it should be easy to discuss the requirements of a customer and the impacts of different AO settings with the customer.

In conclusion, HP 3PAR Adaptive Optimization is an important feature that enables autonomic storage tiering on HP 3PAR storage arrays. However, there are several misunderstandings and misconfigurations of AO that need to be addressed. By following best practices such as using the “Balanced” mode, configuring at least two tiers, and avoiding automated techniques for data movement between different storage tiers, it is possible to ensure optimal performance and cost balancing for customers.