EMC® ScaleIO® is software that creates a server-based SAN from local application server storage to deliver flexible and scalable performance and capacity on demand. It converges storage and compute resources of commodity hardware into a single-layer architecture, aggregating capacity and performance, simplifying management, and scaling to thousands of nodes. As an alternative to a traditional SAN infrastructure, ScaleIO combines HDDs, SSDs, and PCIe flash cards to create a virtual pool of block storage with varying performance tiers. In addition, it provides enterprise-grade data protection, multi-tenant capabilities, and add-on enterprise features such as QoS, thin provisioning, and snapshots. ScaleIO is hardware-agnostic, supports physical and/or virtual application servers, and has been proven to deliver significant TCO savings vs. traditional SAN.

The following three ScaleIO deployment options are supported with RHOSP:
Two layer storage only. This is when the application and storage is installed in separate servers.
Hyperconverged. This is when the application and storage is installed in the same servers.
Hybrid. This is when "two layer" and hyperconverged deployments are mixed in the same ScaleIO cluster