Dynamic parity logging disk arrays for engineering database systems

摘要

RAID (redundant arrays of inexpensive disks) has gained much attention in the recent development of fast I/O systems. Of the five levels, the traditional mirrored disk array still provides the highest I/O rate for small ‘write' transfers. This is because the mirrored disk array has no small ‘write' problem which is found in other levels of RAID. The authors propose a novel RAID architecture for fast engineering database systems, called dynamic parity logging (DPL) disk array. DPL disk array has no small ‘write' problem and can provide much higher ‘write' throughput than other RAID architectures. DPL disk array also has journalling capability, which means that some older design versions are kept for future references. A queueing model for DPL disk array is built. Analytical results, supported by simulation, show that the DPL disk array can provide the highest ‘write' throughput when compared to RAID levels 1, 4, and 5.