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.

Procedure

  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.

What to do next

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