NOTE: This article is for replacing the capacity disk. Please note that how to replace the cache disk is different.
NOTE: Please note that if the cache disk and/or capacity disk is the minimum configuration or deduplication/compression is configured, the procedure after deleting the disk is different from this article.
https://docs.vmware.com/jp/VMware-vSphere/7.0/com.vmware.vsphere.vsan.doc/GUID-2285B446-46BF-429C-A1E7-BEE276ED40F7.html
How To Replace The Capacity Disk
As an example, this article proceeds with the situation where the second capacity disk has a failure in the configuration of one cache disk and 2 capacity disks.
Switch to the maintenance mode from the Actions drop-down menu at the top of the vSphere Web Client.
It is recommended to switch to the maintenance mode before the replacement as long as there is any specific reason.
For more details of switching to the maintenance mode and its types, please refer to the Place a Member of Virtual SAN Cluster in Maintenance Mode.
Delete the applicable physical disk from the Configure menu.
After a while, that disk will not be displayed.
NOTE: The following migration option also must be selected when delete the applicable disk.
For more details, please refer to the Remove Disk Groups or Devices from Virtual SAN.
Physically replace the applicable disk.
Click the ADD DISKS.
Select the newly replaced disk and click ADD.
Verify the capacity is correctly recognized on the vSphere Web Client recognize, release the maintenance mode.
Since the alert remains, delete it manually.