Discrepancy in the available and utilized space in the vSAN cluster

Products

• VMware vSAN

Issue/Introduction

Symptoms:

• Upon comparing the used space on the vSAN cluster and the actual used space from a VM perspective, there is a large difference in both.
• The used space on the entire vSAN cluster will be much more than the combined used space of all the VMs running on the cluster.
• There are no snapshots on the VMs.
• All hard disks attached to the VMs are thin provisioned.

Environment

VMware vSAN 7.x

VMware vSAN 8.x

Cause

This could be due to Missing or Unassociated objects present in the cluster which can still be contributing to the used space in the vSAN cluster.

To verify the Missing objects:

1.) Connecting to one of the vSAN Hosts via SSH/Putty

2.) Run the following command: 

esxcli vsan debug object list --all | grep -i "path|object uuid"

 

3.) Output shows the missing objects:

Object UUID: #######-####-####-####-#######

Size: 255.00 GB

Type: vdfs

Path: /vmfs/volumes/vsan:#############################/#############.vmdk (Missing)

 

To verify the unassociated objects refer the following article: Procedures for identifying Unassociated vSAN objects

Resolution

To remove the unwanted objects from the vSAN cluster, open a ticket with Broadcom support to assist further.