vsphere-esxi-vcenter-server-55-storage-guide

Chapter 18 Solid State Disks Enablement6 Reboot the host.If SSDs that you plan to use with Flash Read Cache and Virtual SAN already have VMFS datastores, removethe datastores.Local SSDs Are UndetectableIf you query for local SSDs during creation of a Flash Read Cache resource, the ESXi host might not return acomplete list of the local SSDs.ProblemESXi might not be able to automatically detect SSDs, or recognize them as local.CauseESXi does not recognize certain devices as SSDs when their vendors do not support automatic SSDdetection. In other cases, some non-SATA SAS SSDs might not be detected as local. When disks are notrecognized as local SSDs, they are excluded from the list of SSDs available for such features as Flash ReadCache because the feature requires only local SSDs.Solution• If ESXi does not automatically recognize its disks as SSDs, tag them as SSD disks. See “Tag Devices asSSD,” on page 164.• If ESXi does not detect SSD disks as local, manually set them as local. See “Tag Devices as Local,” onpage 167.VMware, Inc. 171