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Article
Tertiary Storage in Multimedia Systems: Staging or Direct Access?
Multimedia Systems
  • Hwee Hwa PANG, Singapore Management University
Publication Type
Journal Article
Version
acceptedVersion
Publication Date
11-1997
Abstract

Multimedia applications that are required to manipulate large collections of objects are becoming increasingly common. Moreover, the size of multimedia objects, which are already huge, are getting even bigger as the resolution of output devices improve. As a result, many multimedia storage systems are not likely to be able to keep all of their objects disk-resident. Instead, a majority of the less popular objects have to be off-loaded to tertiary storage to keep costs down. The speed at which objects can be accessed from tertiary storage is thus an important consideration. In this paper, we propose an adaptive data retrieval algorithm that employs a combination of staging and direct access in servicing tertiary storage retrieval requests. At retrieval time, an object that resides in tertiary storage can either be staged to and then played back from disks, or the object can be accessed directly from the tertiary drives. We show that a simplistic policy that adheres strictly to staging or direct access does not exploit the full retrieval capacity of both the tertiary library and the secondary storage. To overcome the problem, we propose a data retrieval algorithm that dynamically chooses between staging and direct access, based on the relative load on the tertiary versus secondary devices. A series of simulation experiments confirms that the algorithm achieves good access times over a wide range of workloads and resource configurations. Moreover, the algorithm is very responsive to changing load conditions.

Keywords
  • Data migration,
  • Feedback control,
  • Multimedia server,
  • Storage hierarchy,
  • Tertiary library
Identifier
10.1007/s005300050070
Publisher
Springer Verlag
Creative Commons License
Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International
Additional URL
https://doi.org/10.1007/s005300050070
Citation Information
Hwee Hwa PANG. "Tertiary Storage in Multimedia Systems: Staging or Direct Access?" Multimedia Systems Vol. 5 Iss. 6 (1997) p. 386 - 399 ISSN: 0942-4962
Available at: http://works.bepress.com/hweehwa-pang/75/