Alarm on host as "Host virtual flash resource usage"

Products

• VMware vSphere ESXi

Issue/Introduction

-Alert "Host virtual flash resource usage" is seen on ESXi hosts in the cluster as below.

Environment

VMware vSphere 7.x

Cause

The alert "Host virtual flash resource usage" is triggered when the host's virtual flash resource usage reaches more than 80%. These alerts are purely usage based and even if cleared manually, the flash read cache usage comes down temporarily on the hosts and the alert gets re-triggered again when the usage reaches the maximum limit.

Resolution

These alerts are triggered as a precautionary measure to notify the customer about the resource utilization and there is no option to either disable or clear these alerts automatically.

To clear the alert, edit and reset the virtual flash settings manually on the vCenter UI.

Refer this document for more information: Set Alarm for Virtual Flash Use

Additional Information

The alert indicates that the flash resource usage has exceeded 80%, which can be caused by several factors such as the number of virtual machines using the resource or the size of their disks.

To manage this effectively and clear up space, I recommend the following steps:

1. Review Resource Utilization: Check which virtual machines are utilizing the flash resource heavily. Consider optimizing or resizing them if possible.
2. Clean Up Unused Resources: Identify and remove any virtual machines or disks that are no longer in use.
3. Increase Capacity: If your workload demands it, consider increasing the capacity of your virtual flash resources.

Monitoring these resources regularly can also help you prevent issues before they arise.