Critical alarm "Datastore usage on disk" reported on vCenter UI.

Products

• VMware vSphere ESXi

Issue/Introduction

• "Datastore usage on disk" critical alarms are reported on  "vCenter UI > Triggered alarms"

 

 

Environment

VMware vSphere ESXi 8.x

Cause

• This alarm is triggered when the datastore utilization is above the threshold provided in the vCenter alarm definition.
• In vCenter UI, vCenter > Monitor > Alarm Definitions > Datastore usage on disk  will show the threshold in that environment.

Resolution

To fix the datastore space issue:

• Free up the space on datastore by deleting unnecessary ISO files, templates, old snapshots, etc.

• Migrate the VM to another datastore with sufficient space available

How to Migrate Your Virtual Machine with Storage vMotion

• If above steps are not possible, expand the datastore capacity at the storage level and increase the space from the ESXi level accordingly 

Increase Capacity of vSphere VMFS Datastore.

Additional Information

View Alarm Definitions