Tape Cloud: Scalable and Cost Efficient Big Data Infrastructure for Cloud Computing

Magnetic tapes have been a primary medium of backup storage for a long time in many organizations. In this paper, the possibility of establishing an inter-network accessible, centralized, tape based data backup facility is evaluated. Our motive is to develop a cloud storage service that organizations can use for long term storage of big data which is typically Write-Once-Read-Many. This Infrastructure-as-a-Service (IaaS) cloud can provide the much needed cost effectiveness in storing huge amounts of data exempting client organizations from high infrastructure investments. We make an attempt to understand some of the limitations induced by the usage of tapes by studying the latency of tape libraries in scenarios most likely faced in the backing up process in comparison to its hard disk counterpart. The result of this study is an outline of methods to overcome these limitations by adopting novel tape storage architectures, filesystem, schedulers to manage data transaction requests from various clients and develop faster ways to retrieve requested data to extend the applications beyond backup. We use commercially available tapes and a tape library to perform latency tests and understand the basic operations of tape. With the optimistic backing of statistics that suggests the extensive usage of tapes to this day and in future, we propose an architecture to provide data backup to a large and diverse client base.