"Snapshot Creation Fails with Error: 'There are currently X usable fault domains. The operation requires 1 more usable fault domain.'"

Products

• VMware vSAN

Issue/Introduction

When attempting to take a snapshot of a virtual machine (VM) residing on a vSAN datastore, the operation fails with the following error message:

“There are currently 2 usable fault domains. The operation requires 1 more usable fault domain. An error occurred while taking a snapshot: Out of resources."

Environment

VMware vSAN 7.x

 

Cause

The error occurs due to an insufficient number of usable fault domains available for component placement. This is typically caused by a failed cache disk on one of the hosts in the vSAN cluster (out of 3 hosts), leading to a reduced number of usable fault domains.

Resolution

• Check Hardware Status:
  • Verify the physical status of the cache drive on the affected host. If the drive has failed, it needs to be replaced.
    
    
• Re-seat the Drive:
  • If the cache drive is physically present but not recognized, reseat the drive and check if it is detected correctly by the system.
    
    
• Check vSAN Health:
  • Ensure that all components of the vSAN cluster are healthy, with a focus on fault tolerance and redundancy configurations.
    
    
• Reconfigure vSAN Fault Domains:
  • Reconfigure the vSAN fault domains to restore the correct fault tolerance factor and ensure that sufficient redundancy is available across the cluster.