Supporting Dynamic Relocation of Video Data in Disk-Array-Based Video Servers

Although modification operations on multimedia data such as insertion and/or deletion of video clips are rare, they may cause significant degradation of disk I/O performance in disk-array-based video servers. This is because many existing disk-array-based video servers consider only video playback at normal speed and retrieval-oriented VCR-like operations such as fast-forward and rewind without considering relocation of video data. Most conventional video servers provide optimal performance using static placement of video data on multiple disks. In this paper, we propose a method called `SRM (Segment Relocation Method)' which provides uniform loadbalance of disks regardless of the dynamic modification of stored video objects. For modification operations, the segments belonging to the corresponding `round' of disk placement are relocated so that the system guarantees uniform load-balance of multiple disks in all rounds. To justify the significance of the relocation scheme, we evaluate a..