Storage Policy Based Management (SPBM) is a highly customizable framework within vCenter that enables users to have virtual machines, containers and persisent volumes used with containers automatically placed on a desired storage resource via policy. Effectively, it can be considered a storage abstraction layer that enables placement of data based upon what features and/or performance that you want the storage layer to include or exclude. This stands as a significant improvement over the traditional method of selecting an individual datastore or multiple datastores depending on use case. Examples can include: how often or if you want a snapshot or replication policy associated with the volume, what array to use or even performance-based placement to list just a few. By abstracting the storage layer in such a manner, both VMware administrators and their users unchain themselves from having to map a volume or persistent volume claim to the underlying array and can instead focus on placement based upon the storage SLA they need for that particular workload.
For Kubernetes with VMware in particular, the usage of SPBM is required as persistent volume claims, storage classes and other key constructs directly reference SPBM policies by name in YAML file deployment specifications, image registries and during the Workload Management enablement procedure within vCenter.
A prerequisite for this article is to create a vVols datastore on the target vCenter. Setting up vVols on the FlashArray with the vSphere Plugin is straight forward and easily accomplished. The procedure to register VASA can be found at vSphere Plugin: Registering FlashArray VASA Providers and how to mount a vVols datastore can be found t_registering_the_vasa_providers_with_the_everpure_vsphere.html#t_registering_the_vasa_providers_with_the_pure_storage_vsphere__t_registering_the_vasa_providers_with_the_pure_storage_vsphere-tbl1.
VMware vVols differ from VMFS from an SPBM perspective. vVols can import storage information and capabilities directly from the underlying FlashArray that can be used with SPBM, while VMFS relies solely upon user-generated categories and tags built within vSphere. This additional functionality for vVols with SPBM is advantageous in numerous ways as users can directly map policy to storage and have that policy update dynamically if anything is changed. The first section below will provide a simple example of how this works.