Resources Usage of Windows Computer Laboratories (technical report)
Authors
Abstract
Studies focusing on Unix have shown that the vast majority of workstations and desktop computers remain idle for most of the time. In this paper we quantify the usage of main resources (CPU, main memory, disk space and network bandwidth) of Windows 2000 machines from classroom laboratories. For that purpose, 169 machines of 11 classroom laboratories of an academic institution were monitored over 77 consecutive days. Samples were collected from all machines every 15 minutes for a total of 583653 samples.Besides evaluating availability of machines (uptime and downtime) and usage habits of users, the paper assesses usage of main resources, focusing on the impact of interactive login sessions over resource consumptions. Also, recurring to Self Monitoring Analysis and Reporting Technology (SMART) parameters of hard disks, the study estimates the average uptime per hard drive power cycle for the whole life of monitored computers. The paper also analyzes the potential of non dedicated classroom Windows machines for distributed and parallel computing, evaluating the mean stability of group of machines.
Our results show that resources idleness in classroom computers is very high, with an average CPU idleness of 97.93%, unused memory averaging 42.06% and unused disk space of the order of gigabytes per machine. Moreover, this study confirms the 2:1 equivalence rule found out by similar works, with N non dedicated resources delivering an average CPU computing power roughly similar to N/2 dedicated machines. These results confirm the potentiality of these systems for resource harvesting, especially for grid desktop computing schemes. However, the efficient exploitation of the computational power of these environments requires adaptive fault tolerance schemes to overcome the high volatility of resources.