Unable to remove "Improved Virtual Disk Home Storage Policy" from vSAN datastore

Products

• VMware vSAN

Issue/Introduction

This article provides information with regard to the "Improved Virtual Disk Home Storage Policy" on vSAN datastore and alarm "Improved virtual disk infrastructure namespaces storage policy alarm".

Symptoms:
On a vSAN datastore, when the "Improved Virtual Disk Home Storage Policy" is set, it cannot be removed.
An alarm "Improved virtual disk infrastructure namespaces storage policy alarm" is also generated.

Environment

VMware vSAN 7.0.x

Cause

Improved virtual disk home object stores metadata for improved virtual disks (similar to the VM Home object of a virtual machine). Initially, when there are no improved virtual disks (hereafter called IVD or First Class Disk (FCD)) in a vSAN datastore, the "Improved Virtual Disk Home Storage Policy" is empty:



When the first FCD is created, the improved virtual disk home object, comprising of 2 namespaces, fcd and catalog, are created in vSAN datastore and the default vSAN storage policy is applied. Similarly, when a user sets the "Improved Virtual Disk Home Storage Policy", the new policy is applied to the improved virtual disk home object. In case, if the Improved virtual disk home object does not exist, it is created prior to applying the policy. An alarm "Improved virtual disk infrastructure namespaces storage policy alarm" is also generated:

Resolution

The policy information from the "Improved Virtual Disk Home Storage Policy" itself cannot be removed. To remove this would require the Improved virtual disk home object (fcd and catalog namespaces) to be deleted from the vSAN datastore and the history of all the actions performed to manage the life-cycle of the FCDs in vSAN datastore would be lost. It is not recommended to delete the Improved virtual disk home object and this is not supported.
The display of policy under "Improved Virtual Disk Home Storage Policy" of the vSAN datastore is useful information.The alarm in relation to this is benign and can safely be ignored.