Advanced vSphere 5.x Storage – Masking, Multipathing & Filtering

The relationship between a vSphere ESXi host and its shared storage is very important for the solution to work effectively. The storage architecture within vSphere is extensible and this extensibility is known as the Pluggable Storage Architecture often abbreviated to PSA.

The PSA is an open modular framework that coordinates the simultaneous operation of multiple multi pathing plugins (MPPs). PSA is a collection of VMkernel APIs that allow third party hardware vendors to insert code directly into the ESX storage I/O path. This allows 3rd party software developers to design their own load balancing techniques and failover mechanisms for particular storage array. The PSA coordinates the operation of the NMP and any additional 3rd party MPP.