Data Protection - Local protection - vSAN datastore storage capacity health

Products

• VMware vSAN

Issue/Introduction

This article explains the purpose and details of the 'vSAN datastore storage capacity health' health check and provides details on why it would report error state.

 

Environment

VMware vSAN 9.1

Resolution

Q: What does the 'vSAN datastore storage capacity health' health check do?

This health check monitors the vSAN datastore capacity to ensure there is sufficient space for local vSAN snapshot operations.

The error threshold is set at 70% datastore usage, and a warning is triggered at 50% usage. If datastore usage reaches 70% and local vSAN snapshots are enabled, snapshot creation is paused.

 

Q: What does it mean when it is in a warning or error state?

The health check reports a warning when the vSAN datastore used capacity exceeds the configured warning threshold (50%), and reports an error once it exceeds the error threshold (70%).

 

Q: How does one troubleshoot and fix the warning or error state?

Resolving this issue requires the vSAN datastore usage be lowered below the warning/error thresholds (50/70%) by either adding more capacity to the datastore or reducing the usage.

Firstly, ensure that the vSAN datastore size and usage are valid e.g. that there are no missing/unmounted capacity devices, no nodes in Maintenance Mode or isolated from the cluster resulting in the vSAN datastore being reduced in size  (e.g. that the vSAN datastore capacity is the expected size based on the cluster configuration).

Consider expanding the vSAN datastore size by either adding more hosts (with disks) or disks to each existing host and claiming them for vSAN usage.

Determine if there is any scope for reducing vSAN datastore usage e.g.: cleanup of any data that is no longer needed, migrating some VMs to alternative datastores, using TRIM/UNMAP to reclaim space etc.