Starting with vSphere 5.5 Update 1, you can use the vSAN feature for high-performance storage and policy-based management.
With vSAN, the locally attached physical storage disks available on a cluster of vSphere hosts are aggregated into one virtual datastore. You specify this datastore when creating a desktop pool, and the various components, such as virtual machine files, replicas, user data, and operating system files, are placed on the appropriate solid-state drive (SSD) disks or direct-attached hard disks (HDDs).
Horizon 7 defines virtual machine storage requirements, such as capacity, performance, and availability, in the form of default storage policy profiles, depending on the pool settings used. Storage is provisioned and automatically configured according to the assigned policies.
The space reclamation feature is not supported if your virtual machine desktops are hosted on vSAN datastores.