vmMo
vmdks := []string{}
for _, device := range vmMo.Config.Hardware.Device {
    switch disk := device.(type) {
    case *types.VirtualDisk:
        fileName := disk.GetVirtualDevice().Backing.(types.BaseVirtualDeviceFileBackingInfo).GetVirtualDeviceFileBackingInfo().FileName
        vmdks = append(vmdks, fileName)
    }
}