An aggregation volume includes a plurality of sub-volumes. Advanced storage functions or operations are carried out at the aggregation volume granularity and therefore are carried out on all sub-volumes allocated in a single aggregation volume at the same time. Such organization results in a de facto consistency group for all sub-volumes associated with a single aggregation volume. To create a sub-volume the aggregation volume is logically divided into pre-defined size chunks. Each chuck can subsequently be allocated to the sub-volume. When a sub-volume is created it is allocated to a number of chunks according to a requested sub-volume size.