On Configuring Hierarchical Multimedia Storage Managers
Shahram Ghandeharizadeh, Hsun-Ko Chan,
Martha L. Escobar-Molano and Xiangyu Ju
Computer Science Department
University of Southern California
February 3, 1994
Multimedia information systems have emerged as an essential component of many application domains ranging from library information systems to entertainment technology. A challenging task when implementing these systems is to support a continuous display of multimedia objects. The challenging is due to the low I/O bandwidth of the current disk technology, the high bandwidth requirement of multimedia objects, and the large size of these objects which requires them to be almost always disk resident. One approach to resolve this limitation is to decluster a multimedia object across multiple disk drives in order to employ the aggregate bandwidth of several disks to support its continuous retrieval (and display). To provide on-line access to vast amount of data economically, the storage architecture of these systems is expected to be hierarchical.
Assuming a hierarchical storage manager that consists of some memory, D disk drives, and a tertiary storage device, this paper describes: 1) a technique to support a continuous display of possibly compressed multimedia objects, and 2) the fundamental factors that impact a choice of configuration parameters for the system, and an algorithm to compute them.
During the past decade, information technology has evolved to store and retrieve multimedia data (e.g., audio, video). Multimedia information systems utilize a variety of human senses to provide effective means of conveying information. Already, these systems play a major role in educational applications, entertainment technology, and library information systems. A challenging task when implementing these systems is to support a continuous retrieval of an object at the bandwidth required by its media type [SAD+93, MWS93, GRAQ91] (in order to ensure its continuous display). This is challenging because certain media types, in particular video, require very high bandwidths. For example, the bandwidth required by NTSC1 for etwork-quality" uncompressed video is approximately 45 megabits per second (mbps) [Has89]. Recommendation 601 of the International
1The US standard established by the National Television System Committee.