How to calculate the vSAN datastore Total Capacity

Products

• VMware vSAN

Issue/Introduction

This document provides the methodology for accurately calculating the Total capacity of vSAN datastore in an OSA Cluster This is essential for planning a new vSAN Cluster deployment or expansion for an existing vSAN OSA cluster.

Environment

VMware vSAN 7.x - OSA
VMware vSAN 8.x - OSA

Resolution

To determine the Total raw capacity (in TB) of vSAN datastore in a vSAN OSA Cluster:

{Total vSAN datastore Capacity (TB)} = {Number of Hosts in vSAN Cluster} x {Number of Capacity Disks per Host} x {Size of the Capacity Disk(TB)}

Note: This calculation is only applicable if all the vSAN hosts are having identical capacity disk configuration.


Example:
Number of Hosts in vSAN Cluster = 4
Number of Capacity Disks per host = 6
Capacity Disk size = 3.49 TB

Total vSAN datastore Capacity = 4 * 6 * 3.49TB = 83.76 TB

Note: The above calculation is for total raw capacity. See Designing and Sizing vSAN Storage which goes over overhead usage and required slack space. You can also use the vSAN Sizer to help plan and design your vSAN cluster.

Additional Information