A queueing model is developed for a multiRAID storage system implemented on modern zoned disks, using ﬁne, accurate access time functions. An extension of a previous analytical model that utilizes Fork-Join composition of M/G/1 queues, it describes zoning directly in terms of the probability distributions or moments of the model's components, such as seek time, rotational latency and data transfer time. These quantities are calculated directly using the principles of operation of the hardware. This is in contrast to estimating them from simulations and theoretical bounds, as in previous zoned disk models. The resulting multiRAID model turns out to be accurate, when its performance predictions, characterized here by the mean of queueing and response times, are compared with simulation, and also scalable; not only for the zoned technology but also for alternate ones.
This paper won the Best Paper Award.
Information from pubs.doc.ic.ac.uk/multiraid-hpcs2007.