I'm not sure to what extent there can be a 'total war'. Clausewitz saw total war as a theoretic abstraction, as no state could mobilise all of its population and resources towards the war effort, there is always going to be some need for domestic goods, luxuries, and other items that are non-essential, whether there is a an open market for them, or resources are diverted from the war effort towards a black economy (which would be a kind of Clausewitzian 'friction' on the home front.

'Totality' as a measure of the degree to which a state mobilises a population and economy can be a useful measure in some senses (like GDP in economics is a useful measure, but not conclusive), as you can track a state's commitment to achieving its goals, and whether it becomes more or less committed over time. A good example of this is the Confederacy in the American Civil War, where it can be tracked that the limited mobilisation of the early period gave way first to conscription, then a levee en masse, then just before defeat the promise of freedom for black men who would fight on behalf of the Confederacy, at every stage moving towards the theoretical 'totality'.

Most often I think total war is used by those within a war a rhetorical device, as by Ludendorff or Goebbels.

Lots of people have tried to make the distinction but it can be difficult. In general a 'regular' war is limited, in terms of reach, how long it lasts and who it effects. A total war on the other hand affects everyone within the state that is at war, and requires all the available resources. This is an oversimplification obviously because there are lots of wars that don't entirely fit into either category.