It is the VMware Storage and Availability technical document site
The site is broken down into three separate sections
Hyperconverged Infrastructure technical resources. vSAN documents to help you at every stage with HCI, from evaluation to optimization.
Storage topics fundamental to vSphere and ESXi including information about VMFS and other storage enhancements.
VMware Site Recovery Manager is the industry-leading solution to enable application availability and mobility across sites in private cloud environments.