A method for data storage includes assigning multiple different portions of a given object, which is stored in non-volatile storage, for access by multiple respective software modules running on one or more processors. Storage operations are performed by the software modules in the portions of the given object. Respective local values, which are indicative of most-recent times the storage operations were performed in the given object by the respective software modules, are updated by the software modules. A global value is updated for the given object, by consolidating updates of the local values performed by the software modules.