When flash devices are not automatically identified as flash by ESXi hosts, you can manually mark them as local flash devices.

This can also happen when they are enabled for RAID 0 mode rather than passthrough mode. When devices are not recognized as local flash, they are excluded from the list of devices offered for Virtual SAN and you cannot use them in the Virtual SAN cluster. Marking these devices as local flash makes them available to Virtual SAN.


  • Verify that the device is local to your host.
  • Verify that the device is not in use.
  • Make sure that the virtual machines accessing the device are powered off and the datastore is unmounted.


  1. Navigate to the Virtual SAN cluster in the vSphere Web Client.
  2. Click the Configure tab.
  3. Under Virtual SAN, click Disk Management.
  4. Select the host to view the list of available devices.
  5. From the Show drop-down menu at the bottom of the page, select Not in Use.
  6. Select one or more flash devices from the list and click the Mark the selected disks as flash disks icon ().
  7. Click Yes to save your changes.
    The Drive type for the selected devices appear as Flash.