The Einstein equation of state as the Clausius relation with an entropy production

We give a modified derivation of the Einstein equation of state by considering the Clausius relation TδS−δN=δQ on a null hypersurface with a non-vanishing expansion (θ≠0), i.e. not in the equilibrium. The derivation corresponds to choosing a specific observer to the hypersurface, and such a generalization gives a hint how we can improve the original derivation by Jacobson. We also give an interpretation of the thermodynamic relation based on the Noether charge method.