Scalable video data placement on parallel disk arrays

We present three strategies for placement of video data on parallel disk arrays. Using a low- level disk model and video data from a scalable subband coding technique, we derive constraints with which to compare the three strategies. One strategy, constant frame grouping, is shown to be superior. Two methods for interleaving multiple videos under the constant frame grouping strategy are presented: nonperiodic and periodic. Periodic interleaving is shown to have the advantages of a lower access time and limited scan and pause functions. The constant frame grouping strategy is tested on an actual array of 8 disks and shown to have performance that is close to the theoretical prediction. The scalable nature of the compressed data is used to relieve the disk system overload for an overly high request rate.