The Datastore showing 0 size in vSphere client UI post Storage array maintenance.

Products

• VMware vSphere ESXi

Issue/Introduction

Symptom :

• From the impacted ESXI host UI, all datastores appear with 0MB capacity.

 

• You may also notice an alert on ESXi :  "The number of vSphere HA heartbeat datastores for this host is 0, which is less than required: 2"

Verification: 

• On other ESXi hosts these datastores are accessible and able to see correct consumed capacity.

• The esxcfg-mpath -b command on ESXi host confirms that all paths to the datastores are active. 

 

Environment

VMware vSphere ESXi 6.x

VMware vSphere ESXi 7.x

VMware vSphere ESXi 8.x

Cause

• The issue occurs when the LUNs are successfully presented to the ESXi host from the storage array, but the datastores are not mounted on the host.

• The output of the esxcli storage filesystem list command shows that all datastores are not mounted (Mounted: false), confirming that although the storage devices are visible at the path level, they are not accessible due to being unmounted.

[root@ESXi_HOST_1:/] esxcli storage filesystem list                        
Mount Point          Volume Name                    UUID                                  Mounted    Type    Size    Free
[Empty Mount point]  DCXXX_2                           65c####-########-####-#########25f    FALSE    VMFS-6    0    0
                     DCXXX_3                           65c####-########-####-#########2cf    FALSE    VMFS-6    0    0
                     DCXXX_4                           65c####-########-####-#########00f    FALSE    VMFS-6    0    0

Resolution

• Manually mount the datastores on the affected ESXi host using the vSphere Client: Mount Datastores

or

• Manually Mount through CLI command on the ESXi host :

esxcli storage filesystem mount -l <datastore_name>

Example : 

esxcli storage filesystem mount -l DCXXX_2

 

Additional Information

Reference article:

List, mount and unmount a volume/VMFS Datastore.

Basic Administrative Operations for vSphere Datastores.

Mount a Datastore with ESXCLI.

HA error: "The number of heartbeat datastores for host is 1, which is less than required: 2"