When local magnetic disks are not automatically identified as HDD devices by ESXi hosts, you can manually mark them as local HDD devices.
If you marked a magnetic disk as a flash device, you can change the disk type of the device by marking it as a magnetic disk.
Verify that the magnetic disk is local to your host.
Verify that the magnetic disk is not in use and is empty.
Verify that the virtual machines accessing the device are powered off.
- Navigate to the vSAN cluster in the vSphere Web Client.
- Click the Configure tab.
- Under vSAN, click Disk Management.
- Select the host to view the list of available magnetic disks.
- From the Show drop-down menu at the bottom of the page, select Not in Use.
- Select one or more magnetic disks from the list and click Mark the selected disks as HDD disks icon ().
- Click Yes to save.
The Drive Type for the selected magnetic disks appears as HDD.