A system is provided that includes one or more hardware processors, and a non-transitory storage medium having stored therein instructions that are executable by one or more hardware processors to perform operations including: gathering information concerning thin journal space usage, in a thin journal, by each of a plurality of consistency groups, and the thin journal space comprises a plurality of journal blocks; computing an ideal journal block state for each consistency group; computing an achievable journal block state for each consistency group; and computing a transition step from the achievable journal block state to the ideal journal block state.