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

1

In the vSphere Web Client, browse to the virtual machine.

2

Right-click the virtual machine and select Edit Settings.

3

Click the Virtual Hardware tab.

4

Click the Hard Disk triangle to expand the hard disk options.

The Type text box shows the format of your virtual disk.

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