After you create a vVols datastore, it remains inaccessible.
The vSphere Client shows the datastore as inaccessible. You cannot use the datastore for virtual machine provisioning.
This problem might occur when you fail to configure protocol endpoints for the SCSI-based storage container that is mapped to the virtual datastore. Like traditional LUNs, SCSI protocol endpoints need to be configured so that an ESXi host can detect them.
Before creating virtual datastores for SCSI-based containers, make sure to configure protocol endpoints on the storage side.