Abstract
Distributed storage systems with content hash ID mechanism previously didn’t specifically consider to reclaim the storage space of unnecessary data. The lease time method is used commonly but it leads inefficient resource consumption. In this letter, we propose a composition of two reference counters and two supplemental timer fields to delete unnecessary data explicitly. We explain it as a concrete design for WOODS to introduce the delete feature without expensive procedure such as multiple and synchronized locks. It also resists to the abnormal termination of application. This letter also shows the proposal mechanism works efficiently than traditional lease time method for archiving system.