Connected ESXi hosts fail to display the datastore and VM size showing 0KB.

Products

• VMware vSphere ESXi 7.0

Issue/Introduction

Symptoms:

After storage maintenance, ESXi hosts that were connected to the storage do not show the datastore, and the backing device for the datastore shows as "Not consumed."
And VM servers are inaccessible with 0KB disk size.

When the user runs the command "df -h" to list the datastore from the ESXi CLI where the datastore is not visible, they get the following message.

[root@esxi:~] df -h
VmFileSystem: Slow refresh failed: Unable to get FS Attrs for /vmfs/volumes/66cxxxx-xxxxxxxx-xxxx-xxxxxxx
Error when running esxcli, return status was: 1
Errors:
Error getting data for filesystem on '/vmfs/volumes/66cxxxxx-xxxxxxxx-xxxx-xxxxxxx': Unable to get FS Attrs for /vmfs/volumes/66cxxxxx-xxxxxxxx-xxxx-xxxxxxx, skipping.

Where "66cxxxx-xxxxxxxx-xxxx-xxxxxxx" is the UUID of the concerned datastore which is not showing on the concerned ESXI host.

The user can see the backing extent and can also get the partition information from the concerned ESXi host from the UI.

Environment

VMware vSphere ESXi 7.x

VMware vSphere ESXi 8.x

Cause

The backing device of the datastore appear as "not consumed" due to temporary inconsistencies such as memory glitches on the ESXi host, transient network disruptions, or file system irregularities. 

Resolution

• Perform a storage rescan first, Check the following KB on how to perform rescan of the storage on an ESXi host.
  
  Performing a rescan of the storage on an ESXi host
  
  
• If the storage rescan does not work, then reboot the ESXi host.