This issue of the Computer Journal is a special issue of the 6th European Performance Engineering Workshop (EPEW 2009), held at Imperial College London during 9–10 July 2009. EPEW has a successful record of gathering performance modelling, analysis and experience papers over the past 7 years and EPEW 2009 was no exception. EPEW 2009 was the first in the EPEW series to be held in the UK, followi...

A recent queueing-based modelling methodology of RAID systems compared the mean disk access times of the two most common variants, RAID0-1 and RAID5, as well as a multi-RAID system in which they coexist. Accesses to multiple disks occur concurrently for each logical (user) request and complete only when every disk involved has completed. The models therefore needed to estimate the mean value of...

For the actual Video-On-Demand (VOD) service environment, we implement a cluster-based VOD server composed of general PCs and adopt the parallel processing for MPEG movies. For the implemented VOD server, a video block recovery mechanism is designed on the RAID-3 and the RAID-4 algorithms. However, without considering the architecture of cluster-based VOD server, the application of these basic ...

Over the past five years, large-scale storage installations have required fault-protection beyond RAID-5, leading to a flurry of research on and development of erasure codes for multiple disk failures. Numerous open-source implementations of various coding techniques are available to the general public. In this paper, we perform a head-to-head comparison of these implementations in encoding and...

investigations are carried out to evaluate the performance of a low heat rejection (lhr) diesel engine consisting of air gap insulated piston with 3-mm air gap, with superni (an alloy of nickel) crown and air gap insulated liner with superni insert with different operating conditions of crude jatropha oil with varied injection timing and injection pressure.  performance parameters of brake ther...