Thick provisioned vSAN file share may take additional space compared with the data stored in the file share

Products

• VMware vSphere ESXi

Issue/Introduction

When a thick provisioned vSAN file share (with non-zero proportional capacity as in the storage policy) is created, the actual space usage on vSAN might be significantly more than the data stored in the file share. The reason is that the backend vSAN object will become thick provisioned if the vSAN file share is set to a thick storage policy.

The detailed vSAN object provisioning algorithm is the following.

1. If the user sets the quota for the file share, we will take the quota as the initial vSAN object. In the case of share growth, i.e., increase the share quota, another vSAN object with the same storage policy will be created when the quota of the initial vSAN object is hit.
2. If the user does not set the quota, we will take 255GB as the initial vSAN object size to provision, and this 255GB size will be taken as the step size to create further vSAN objects.

Environment

VMware vSphere ESXi 7.0.0
VMware vSphere 7.0.x

Resolution

The above code was introduced in vSAN 7.0 Update 1 for better handling of the space calculation.