The VMFS datastore could not be expanded Error: Failed to expand VMFS datastore datastore1 - Cannot change the host configuration

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms : 

• Unable to expand the datastore from vSphere client , vCenter server and CLI. 
• You receive this error message similar to: 
  Error: Failed to expand VMFS datastore datastore1 - Cannot change the host configuration.

     

• From CLI you receive this error message similar to : 

   

• Backend LUN was expanded but unable to expand the datastore. 

 

Environment

VMware vSphere ESXi 7.x

VMware vSphere ESXi 8.x

Cause

The datastore was identified as a snapshot, which led to this problem.

You will see similar event in vmkernel.log: 

LVM: 11764: Device naa.####################:1 detected to be a snapshot:
LVM: 11770:   queried disk ID: <type 2, len 22, lun 0, devType 0, scsi 0, h(id) 15436777671286394200>
LVM: 11777:   on-disk disk ID: <type 2, len 22, lun 0, devType 0, scsi 0, h(id) 16841058529903986994>

Resolution

Follow the below steps to resolve the issue : 

1. Power off virtual machine present in affected data store. 

2. Removed the VMs from inventory to avoid any conflict during datastore operations.

3. Unmounted the datastore from the host. Command : How to List, mount and unmount a volume/VMFS Datastore.

4. Performed a resignature of the datastore to generate a new UUID and remove the snapshot flag.command : esxcli storage vmfs snapshot resignature -l "datastore-name"

5. Remounted the datastore post-resignature. How to List, mount and unmount a volume/VMFS Datastore.

6. Successfully expanded the datastore to include the newly added LUN capacity.

7. Re-registered the virtual machines. 

 Refer  Troubleshooting LUNs detected as snapshot LUNs in vSphere for more information. 

Additional Information

Troubleshooting LUNs detected as snapshot LUNs in vSphere

Failed to expand VMFS datastore - Cannot change the host configuration