Geographically Distributed System for Catastrophic Recovery

This paper presents the results of a proof-of-concept implementation of an on-going project to create a cost effective method to provide geographic distribution of critical portions of a data center along with methods to make the transition to these backup services quick and accurate. The project emphasizes data integrity over timeliness and prioritizes services to be offered at the remote site. The paper explores the tradeoff of using some common clustering techniques to distribute a backup system over a significant geographical area by relaxing the timing requirements of the cluster technologies at a cost of fidelity. The trade-off is that the fail-over node is not suitable for high availability use as some loss of data is expected and fail-over time is measured in minutes not in seconds. Asynchronous mirroring, exploitation of file commonality in file updates, IP Quality of Service and network efficiency mechanisms are enabling technologies used to provide a low bandwidth solution for the communications requirements. Exploitation of file commonality in file updates decreases the overall communications requirement. IP Quality of Service mechanisms are used to guarantee a minimum available bandwidth to ensure successful data updates. Traffic shaping in conjunctio