Provide enough disk space for Virtual SAN and for the virtualized workloads that use the Virtual SAN datastore. Preparing Storage DevicesUse flash devices and magnetic disks based on the requirements for Virtual SAN. Mark Flash Devices as Capacity Using ESXCLIYou can manually mark the flash devices on each host as capacity devices using esxcli. Untag Flash Devices Used as Capacity Using ESXCLIYou can untag flash devices that are used as capacity devices, so that they are available for caching. Mark Flash Devices as Capacity using RVC Run the vsan.host_claim_disks_differently RVC command to mark storage devices as flash, capacity flash, or magnetic disk (HDD). Parent topic: Preparing a New or Existing Cluster for Virtual SAN