Create snapshot Error: "There are currently 4 usable fault domains. The operation requires 1 more usable fault domains."

Products

• VMware vSAN 8.x

Issue/Introduction

1. Snapshot  cannot be created on a  (FTT=2) VM. They get the error, "There are currently 4 usable fault domains. The operation requires 1 more usable fault domain."
2. New VM can not be created with default policy, which is also same with the VM policy.
3. The "Force provisioning" Option is not enabled on the policy
4. There are 5 hosts, each host has one diskgroup.

Environment

VMware vSAN 

Cause

Customer runs FTT=2 policy on a 5-host Cluster but one host's diskgroup got offline.

Resolution

Clean up diskgroup setting and replace disk and re-create diskgroup. Refer Managing and Configuring a vSAN disk group using esxcli commands
To create VM temply, change the datastore default policy back to vSAN default policy (FTT=1). Refer Change the Default Storage Policy for vSAN Datastores