2012 International Green Computing Conference (IGCC)

This paper examines the energy costs of different approaches to full disk encryption, including hardware encryption, software encryption, and "no encryption". Using the DEEP power measurement platform, we measured the energy consumed by each configuration under various workloads. We demonstrate that hardware encryption saves energy for many (though not all) workloads, but that the energy savings m... View full abstract»

Persistent data storage is a necessity in local cloud computing architectures. This research investigates how these architectures can reduce their energy consumption by dynamically scaling the number of storage nodes needed to accommodate user's needs. While a user is actively using cloud computational resources, their accommodating persistent data is stored on hot storage nodes that are powered o... View full abstract»

The decreasing cost of disk drives has made it possible to maintain large-scale storage systems and to achieve high performance for I/O demanding applications. One possible optimization that can be applied to these types of systems is to move the I/O load to a subset of the disks; so that the commonly accessed data resides in a set of `popular' disks, whereas the `unpopular' disks can stay in low ... View full abstract»

In this paper, we explore academic data center utilization rates from an energy management perspective with the broader goal of providing decision support for green computing. The utilization rate is defined as the overall extent to which data center servers are being used and is usually recorded as a percentage. Recent literature states that utilization rates at many data centers are quite low re... View full abstract»

To migrate virtual machines requires not only time but also energy. If pursuing a follow-the-renewables computing paradigm, migrating virtual machines between data centres on the basis of clean energy availability, understanding not only the time requirements of migration but also its energy consumption is key. Existing research has paid little attention to the energy required to perform virtual m... View full abstract»

As the cloud markets grow, the cloud providers are faced with new challenges such as reduction of power consumption and guaranteeing service level agreements (SLAs). One reason for these problems is the use of server consolidation policy based on virtualization technologies for maximizing the efficiency of resource usage. Because current virtualization technologies do not ensure performance isolat... View full abstract»

Cloud computing has been emerging as a flexible and powerful computational architecture to offer ubiquitous services to users. It accommodates interconnected hardware and software resources in a unified way, which is different to traditional computational environments. A variety of hardware and software resources are integrated together as a resource pool, the software is no longer resided in a si... View full abstract»

Ancillary services are the mechanisms power grids use to address short-term variability in supply and demand as well as the impact of power plant or transmission line failures. Organizations providing such services can earn revenue, or at least reduce their energy costs. This paper explores options for large data centres to reduce costs in this way. Simulation results are presented for a system th... View full abstract»

Data centers can lower costs significantly by pro-visioning expensive electrical equipment (such as UPS, diesel generators, and cooling capacity) for the actual peak power consumption rather than server nameplate power ratings. However, it is possible that this under-provisioned power level is exceeded due to software behaviors on rare occasions and could cause the entire data center infrastructur... View full abstract»

Cooling is an important issue in data center design and operation. Accurate evaluation of a design or operational parameter choice for cooling is difficult as it requires several runs of computationally intensive Computational Fluid Dynamics (CFD) based models. Therefore there is need for an exploration method that does not incur enormous computation. In addition, the exploration should also provi... View full abstract»

Although many real-world signals are known to follow standard models, signals are usually first sampled, rather wastefully, at the Nyquist rate and only then parametrized and compressed for efficient transport and analysis. Compressed sensing (CS) is a new technique that promises to directly produce a compressed version of a signal by projecting it to a lower dimensional but information preserving... View full abstract»

Both performance and energy cost are important concerns for current data center operators. Traditionally, however, IT and mechanical engineers have separately optimized the cyber vs. physical aspects of data center operations. In contrast, the work presented in this paper jointly considers both the IT - cyber - and the physical systems in data centers, the eventual goal being to develop performanc... View full abstract»

We consider scheduling tasks that arrive over time on a speed scalable processor. At each time a schedule specifies a job to be run and the speed at which the processor is run. Processors are generally less energy efficient at higher speeds. We seek to understand the structure of schedules that optimally trade-off the energy used by the processor with a common scheduling quality of service measure... View full abstract»

To avoid ecological collapse, we must manage Earth's ecosystems sustainably. Viewed as a control problem, the two central challenges of ecosystem management are to acquire a model of the system that is sufficient to guide good decision making and then optimize the control policy against that model. This paper describes three efforts aimed at addressing the first of these challenges-machine learnin... View full abstract»

The mapping of the power delivery network to the equipment in a data center is an essential step towards having intelligent and efficient control over data center power distribution. Visual identification of the power connectivity is error-prone and expensive while other methods require high-power signal injection and significant human labor or interruption in the power delivery, making them impra... View full abstract»

While sleep states have existed for mobile devices and workstations for some time, these sleep states have not been incorporated into most of the servers in today's data centers. High setup times make data center administrators fearful of any form of dynamic power management, whereby servers are suspended or shut down when load drops. This general reluctance has stalled research into whether there... View full abstract»

This paper presents HeteroMates, a solution that uses heterogeneous processors to extend the dynamic power/performance range of client devices. By using a mix of different processors, HeteroMates offers both high performance and reduced power consumption. The solution uses core groups as the abstraction that groups a small number of heterogeneous cores to form a single execution unit. Group hetero... View full abstract»

Fast thermal maps are a crucial component for many green data center design techniques. However, most state of the art work on thermal mapping ignores critical temporal aspects of thermal behavior and relies on modeling assumptions, such as the steady state assumption, that can reduce their accuracy and cause heat-induced performance throttling when used for task scheduling. These problems have th... View full abstract»

Surprisingly little is known about underwater marine environments and ecosystems owing to several factors. One important factor has been the general inability to observe and monitor these massive subsurface ocean spaces. Despite significant advances in sensor, communication and computing technology, underwater sensor platforms are generally inferior to their terrestrial counterparts. Here we highl... View full abstract»

Until now, green computing research has largely relied on few, short-term power measurements to characterize the energy use of enterprise computing. This paper brings new and comprehensive power datasets through Powernet, a hybrid sensor network that monitors the power and utilization of the IT systems in a large academic building. Over more than two years, we have collected power data from 250+ i... View full abstract»

As scientific data is reaching exascale, scalable and energy efficient data analytics is quickly becoming a top notch priority. Yet, a sustainable solution to this problem is hampered by a number of technical challenges that get exacerbated with the emerging hardware and software technology trends. In this paper, we present a number of recently created “secret sauces” that promise to address some ... View full abstract»

It has recently been proposed that Internet energy costs, both monetary and environmental, can be reduced by exploiting temporal variations and shifting processing to data centers located in regions where energy currently has low cost. Lightly loaded data centers can then turn off surplus servers. This paper studies online algorithms for determining the number of servers to leave on in each data c... View full abstract»

This paper describes a simulation to establish the extent to which reliance on non-dispatchable energy sources, particularly wind generation, could in the future be extended beyond accepted norms, by utilizing the distributed battery capacity of an electric vehicle fleet for storage. The notion of exploiting the distributed battery capacity of an electric vehicle fleet as grid storage is not new. ... View full abstract»

Computing is poised to make major contributions to the global sustainability effort by engaging the fields of energy efficiency, renewable energy generation, and energy delivery. This paper discusses three near term opportunities for computing in the field of building energy efficiency. Integrated design uses building energy modeling to search for ultra-efficient buildings tailored to use requirem... View full abstract»

Heating, ventilation, and cooling (HVAC) accounts for 38% of building energy usage, and over 15% of all US energy usage, making it one of the nation's largest energy consumers. Many attempts have been made to optimize the control of HVAC systems by minimizing the energy wasted in conditioning buildings that are unoccupied. Systems have been proposed that turn off HVAC systems when a house is unocc... View full abstract»