How to View Actual vSAN Data Usage in vSphere Client

Products

• VMware vSAN

Issue/Introduction

Actual data usage on a vSAN cluster is not clearly visible when reviewing datastore-level capacity information in the vSphere Client.
The datastore view primarily reflects total space consumption and does not explicitly show the breakdown of VM and user object data usage.

This information is required for accurate capacity assessment and planning activities such as backup solution sizing.

Environment

VMware vSAN 8.0

Resolution

To view detailed vSAN data usage, perform the following steps:

1. Log in to the vSphere Client.
2. Select the vSAN Datastore from the Datastore inventory.
3. Navigate to:  Monitor > vSAN > Capacity
4. Select VIEW CAPACITY.
5. Select EXPAND ALL to display the detailed capacity breakdown.

This view provides visibility into actual VM and user object data usage rather than aggregated datastore consumption.

Additional Information

Capacity Usage Breakdown Details

1 VM (User Objects) Usage

This section reflects capacity consumed by virtual machine objects stored on the vSAN datastore.

VMDK capacity consumption is divided into the following categories:

1. Primary Data
• Represents the actual user data written to physical disks
• Does not include any storage policy or RAID overhead
2. Replica Usage
• Represents the RAID overhead applied by the assigned storage policy
• Includes mirroring or parity data associated with RAID-1 or RAID-5/6 configurations

This separation provides clarity between actual data and data protection overhead.

2 Non-VM (User Objects) Usage

This section includes capacity consumed by non-VM objects stored on the vSAN datastore, such as:

• ISO files
• VM templates
• vSAN file shares/ vSAN iSCSI
• Other user-created objects