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 does not have the 'small write problem' which is found in other levels of RAID. The authors propose a novel RAID architecture for fast engineering database systems, called a dynamic parity logging (DPL) disk array. A DPL disk array does not have the 'small write problem' and can provide much higher throughput than other RAID architectures. The DPL disk array also has a journalling capability, which means that some older design versions are kept for future reference. A queueing model for the DPL disk array is built. Analytical results, supported by simulation, show that the DPL disk array can provide higher 'write' throughput when compared to RAID levels 1, 4, and 5.