Unable to perform fstrim on any of the virtual machines in the vSAN Cluster

Products

• VMware vSAN 8.x
• VMware vSAN 7.x

Issue/Introduction

Symptoms:

• Upon running fstrim on Linux virtual machine hosted on vSAN cluster, it reported an error "fstrim path the discard operation is not supported".

         

Environment

VMware vSAN 7.x

VMware vSAN 8.x

Cause

• The issue is seen when Guest unmap/trim service is not enabled on vSAN cluster services. If the unmap/trim is not enabled at the vSAN layer, it would not allow the fstrim to function at the guest layer.

         fstrim: /var/log/:the discard operation is not supported

• By default, Trim/Unmap is not enabled in vSAN Cluster .

         

Resolution

• Enable unmap/trim on vSAN using the steps below.
• Reference KB details .

         Procedure to Enable TRIM/UNMAP