A novel data placement scheme on continuous media servers with zone-bit-recording disks

The development of continuous media servers has been growing rapidly in recent years. In general, these servers consist of multiple Zone-Bit-Recording (ZBR) disks. One key issue in developing continuous media servers is the allocation of data into ZBR disks. The authors propose a novel data placement scheme, called VARBT (variable block-size and data-transfer-time), to fully utilize the characteristics of ZBR disks. The proposed scheme determines data block size in each zone completely, according to the capacity of that zone, thus the storage utilization is 100% in this scheme. During the process of data retrieval, the data transfer rate for each block is equal to the bandwidth of each physical zone, thus the bandwidth utilization is also maximal. Through comparison with two other schemes proposed in the literature, we found that the VARBT scheme has the smallest average block size, required memory space and system response time to support more simultaneous streams. More importantly, the VARBT scheme achieves 100% storage utilization and bandwidth utilization.