ADSM: A multi-platform, scalable, backup and archive mass storage system

Abstract

The ADSTAR Distributed Storage Manager (ADSM) is a client-server system whose goal is to provide the illusion of infinite storage for a range of applications. The first deployed application is backup and archive services. ADSM is a configurable system targeted to serve any client at user installations with heterogeneous architectures that offers the same level of data management for LANs, midrange and mainframe systems. ADSM moves the responsibilities of backup and archive media management to the server while maintaining the benefits of local workstation systems. In ADSM, incremental backups are all that a user needs to do to restore its data with maximum performance. The ADSM server has been deployed in five IBM and two non-IBM platforms, while the ADSM clients operate in more than twelve IBM and non-IBM platforms. ADSM is built to administer a petabyte of storage in an open-ended variety of storage devices. The system can handle a billion entities at a sustained level of storage and retrieval performance. Entities stored in ADSM can be up to 2 bytes in size. In ADSM, storage management and data access services are provided on demand to users through direct GUI-based interfaces, as well as through policy-based background processing. In ADSM there are no practical limits to the number of users that can store files in a server, the amount of policies to administer the data of these users, and the number of computing and communication platforms in which the system can operate. Database technology is central in implementing our goal to provide unbounded storage for applications. In ADSM all activities are done within transactions. We have incorporated the latest algorithmic developments that allow us to operate continuously while retaining up to three copies of our metadata in a replicated manner.