You can determine whether your virtual disk is in thick or thin format.

If you have thin provisioned disks, you can change them to thick by selecting Flat pre-initialized disk provisioning. You change thick provisioned disks to thin by selecting Allocate and commit space on demand.

1

Right-click a virtual machine in the inventory and select Edit Settings.

2

On the Virtual Hardware tab, expand Hard disk.

The disk type is displayed in the Disk Provisioning field.

3

Click OK.

If your virtual disk is in the thin format, you can inflate it to its full size using the vSphere Web Client.