Data availability is a desirable feature for all cloud providers. However, adoption of disaster recovery will bring incremental cost due to the continued investment of hardware. This paper illustrates the existing assurance mechanisms for data reliability and points out that the data availability and disaster recovery cost are always two incompatible goals for cloud providers. A rich cloud based disaster recovery (DR) model is designed for cloud providers. In this model, multiple rich cloud proxies are employed in order to reduce the response time and improve the quality of service. With help of this system, a cloud provider is able to replicate data with lower cost by utilizing the virtual resource from other clouds. In order to minimize the DR cost while guaranteeing the data availability, a cost aware high data reliability provision algorithm (CAHRPA) is proposed to tackle such an optimization problem. In the end, the feasibility and efficiency of this CAHRPA is verified by the comparison with some other replication strategies.