If you query for local flash disks, the ESXi host might not return a complete list of the local flash disks.
ESXi might not be able to detect flash disks, or recognize them as local. This problem can occur when you configure entities that require only local flash disks, for example, virtual flash resource or vSAN.
ESXi does not recognize certain devices as flash disks when their vendors do not support automatic flash disk detection. In other cases, some flash disks might not be detected as local, and ESXi marks them as remote. When the host does not recognize the disks as the local flash disks, it excludes them from the list of disks available for configuration.
You might need to tag the disks as flash or as local.
If ESXi does not automatically recognize its disks as flash disks, tag them as flash disk disks.
If ESXi does not detect flash disks as local, manually set them as local.