Description

Data reliability and storage costs are two primary concerns for current Cloud storage systems. To ensure data reliability, the widely used multi-replica (typically three) replication strategy in current Clouds incurs a huge extra storage consumption, resulting in a huge storage cost for data-intensive applications in the Cloud in particular. In order to reduce the Cloud storage consumption while meeting the data reliability requirement, in this paper we present a cost-effective data reliability management mechanism named PRCR based on a generalized data reliability model. By using a proactive replica checking approach, while the running overhead for PRCR is negligible, PRCR ensures reliability of the massive Cloud data with the minimum replication, which can also serve as a cost effectiveness benchmark for replication based approaches. Our simulation indicates that, compared with the conventional 3-replica strategy, PRCR can reduce from one-third to two-thirds of the Cloud storage space consumption, hence significantly lowering the storage cost in a Cloud.