log more info about disk additions

server/handler/vmModify.go

@@ -204,6 +204,14 @@ func (h *Handler) calculateNewDiskSize(event models.CloudEventReceived) float64
 			// Calculate the total disk allocated in GB
 			for _, device := range vmObject.Vm.Config.Hardware.Device {
 				if disk, ok := device.(*types.VirtualDisk); ok {
+
+					// Print the filename of the backing device
+					if backing, ok := disk.Backing.(*types.VirtualDiskFlatVer2BackingInfo); ok {
+						h.Logger.Debug("Adding disk", "size_bytes", disk.CapacityInBytes, "backing_file", backing.FileName)
+					} else {
+						h.Logger.Debug("Adding disk, unknown backing type", "size_bytes", disk.CapacityInBytes)
+					}
+
 					diskSize += float64(disk.CapacityInBytes / 1024 / 1024 / 1024) // Convert from bytes to GB
 				}
 			}