VM Summary Tab shows the Storage used more than actual space consumed by Guest OS

Products

• VMware vSAN

Issue/Introduction

Symptoms:

• In vCenter UI, the Summary Tab of the Virtual machines in vSAN datastore shows Storage used more than the actual space consumed by the Guest OS.

• In the example figure, the Storage used by the Virtual machine is 33.4 GB. However, the guest OS might be consuming less than this reported space.

Environment

VMware vSAN 7.0.x
VMware vSAN 8.0.x

Cause

Depending upon the Storage policy applied to the Virtual machines, space will be consumed from vSAN datastore.

vSAN Architecture	FTT	RAID	Placement	Space consumption	Minimum Hosts
vSAN OSA / ESA	1	1	1+1 Mirror	2x	3
vSAN OSA / ESA	2	1	1+1+1 Mirror	3x	5
vSAN OSA / ESA	3	1	1+1+1+1 Mirror	4x	7
vSAN OSA	1	5	3+1 Stripe	1.33x	4
vSAN ESA	1	5	2+1 Stripe	1.5x	3
vSAN ESA	1	5	4+1 Stripe	1.25x	6
vSAN OSA /ESA	2	6	4+2 Stripe	1.5x	6

Storage Used will also include the vswp usage for the Virtual machine.

Resolution

This is an expected in a vSAN environment as the space usage is based on the Storage policy used for the Virtual machines.

Additional Information

What are vSAN Policies