The Experts below are selected from a list of 69558 Experts worldwide ranked by ideXlab platform
Willy Zwaenepoel - One of the best experts on this subject based on the ideXlab platform.
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HPCA - Concurrent Direct Network Access for virtual machine Monitors
2007 IEEE 13th International Symposium on High Performance Computer Architecture, 2007Co-Authors: Paul Willmann, Jeffrey Shafer, Aravind Menon, Scott Rixner, David Carr, Willy ZwaenepoelAbstract:This paper presents hardware and software mechanisms to enable concurrent direct network access (CDNA) by operating systems running within a virtual machine monitor. In a conventional virtual machine monitor, each operating system running within a virtual machine must access the network through a software-virtualized network interface. These virtual network interfaces are multiplexed in software onto a physical network interface, incurring significant performance overheads. The CDNA architecture improves networking efficiency and performance by dividing the tasks of traffic multiplexing, interrupt delivery, and memory protection between hardware and software in a novel way. The virtual machine monitor delivers interrupts and provides protection between virtual machines, while the network interface performs multiplexing of the network data. In effect, the CDNA architecture provides the abstraction that each virtual machine is connected directly to its own network interface. Through the use of CDNA, many of the bottlenecks imposed by software multiplexing can be eliminated without sacrificing protection, producing substantial efficiency improvements
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Concurrent direct network access for virtual machine monitors
Proceedings - International Symposium on High-Performance Computer Architecture, 2007Co-Authors: Paul Willmann, Jeffrey Shafer, Aravind Menon, Alan L. Cox, Scott Rixner, David Carr, Willy ZwaenepoelAbstract:This paper presents hardware and software mechanisms to enable concurrent direct network access (CDNA) by op- erating systems running within a virtual machine monitor In a conventional virtual machine monitor; each operating system running within a virtual machine must access the network through a software-virtualized network interface. These virtual network interfaces are multiplexed in software onto a physical network interface, incurring significant per- formance overheads. The CDNA architecture improves net- working efficiency andperformance by dividing the tasks of traffic multiplexing, interrupt delivery, and memory protec- tion between hardware and software in a novel way. The virtual machine monitor delivers interrupts and provides protection between virtual machines, while the network in- terface performs multiplexing ofthe network data. In effect, the CDNA architecture provides the abstraction that each virtual machine is connected directly to its own network in- terface. Through the use of CDNA, many of the bottlenecks imposed by software multiplexing can be eliminated with- out sacrificing protection, producing substantial efficiency improvements.
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diagnosing performance overheads in the xen virtual machine environment
Virtual Execution Environments, 2005Co-Authors: Aravind Menon, Jose Renato Santos, Yoshio Turner, Gopalakrishnan Janakiraman, Willy ZwaenepoelAbstract:virtual machine (VM) environments (e.g., VMware and Xen) are experiencing a resurgence of interest for diverse uses including server consolidation and shared hosting. An application's performance in a virtual machine environment can differ markedly from its performance in a non-virtualized environment because of interactions with the underlying virtual machine monitor and other virtual machines. However, few tools are currently available to help debug performance problems in virtual machine environments.In this paper, we present Xenoprof, a system-wide statistical profiling toolkit implemented for the Xen virtual machine environment. The toolkit enables coordinated profiling of multiple VMs in a system to obtain the distribution of hardware events such as clock cycles and cache and TLB misses. The toolkit will facilitate a better understanding of performance characteristics of Xen's mechanisms allowing the community to optimize the Xen implementation.We use our toolkit to analyze performance overheads incurred by networking applications running in Xen VMs. We focus on networking applications since virtualizing network I/O devices is relatively expensive. Our experimental results quantify Xen's performance overheads for network I/O device virtualization in uni- and multi-processor systems. With certain Xen configurations, networking workloads in the Xen environment can suffer significant performance degradation. Our results identify the main sources of this overhead which should be the focus of Xen optimization efforts. We also show how our profiling toolkit was used to uncover and resolve performance bugs that we encountered in our experiments which caused unexpected application behavior.
Jianzhong Fu - One of the best experts on this subject based on the ideXlab platform.
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modeling and application of virtual machine tool
International Conference on Artificial Reality and Telexistence, 2006Co-Authors: Jianzhong FuAbstract:The recent years of the 21th Century are associated with the advent of virtual reality technologies for modern industry and manufacturing engineering. virtual machine Tool Technology is given to design, test, control and machine parts in a virtual reality environment. This paper presents the methods to model and simulate the virtual machine tools in response to change in the machining requirements. Specifically, a set of module combination rules and a modeling method of the structure of machine tools using connectivity graph are developed. By this way virtual machine tool is implemented. The developed virtual machine tool can be efficiently used for industry training and machine leaning and operating.
Susan V. Vrbsky - One of the best experts on this subject based on the ideXlab platform.
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CLOUD - Performance Metrics of virtual machine Live Migration
2015 IEEE 8th International Conference on Cloud Computing, 2015Co-Authors: Michael Galloway, Gabriel Loewen, Susan V. VrbskyAbstract:Live virtual machine migration allows resources from one physical server to be moved to another with little or no interruption in the processes of the guest operating system. The process involved in performing a live migration includes copying the guest virtual machine memory state and cpu register state from a hyper visor on one server to another. In this paper, virtual machine migration is evaluated in terms of performance of the virtual machine while being migrated, performance of the cloud architecture while migrating the virtual machine, and the power costs of performing a live virtual machine migration. The experiments on virtual machine live migration will give insight on how the cloud architecture responds and handles live migrations, and how virtual machines perform while they are in a migration phase.
Matt Bishop - One of the best experts on this subject based on the ideXlab platform.
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Investigating the Implications of virtual machine Introspection for Digital Forensics
2009 International Conference on Availability Reliability and Security, 2009Co-Authors: Kara Nance, Matt BishopAbstract:Researchers and practitioners in computer forensics currently must base their analysis on information that is either incomplete or produced by tools that may themselves be compromised as a result of the intrusion. Complicating these issues are the techniques employed by the investigators themselves. If the system is quiescent when examined, most of the information in memory has been lost. If the system is active, the kernel and programs used by the forensic investigators are likely to influence the results and as such are themselves suspect. Using virtual machines and a technique called virtual machine introspection can help overcome these limits, but it introduces its own research challenges. Recent developments in virtual machine introspection have led to the identification of four initial priority research areas in virtual machine introspection including virtual machine introspection tool development, applications of virtual machine introspection to non-quiescent virtual machines, virtual machine introspection covert operations, and virtual machine introspection detection.
Aravind Menon - One of the best experts on this subject based on the ideXlab platform.
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HPCA - Concurrent Direct Network Access for virtual machine Monitors
2007 IEEE 13th International Symposium on High Performance Computer Architecture, 2007Co-Authors: Paul Willmann, Jeffrey Shafer, Aravind Menon, Scott Rixner, David Carr, Willy ZwaenepoelAbstract:This paper presents hardware and software mechanisms to enable concurrent direct network access (CDNA) by operating systems running within a virtual machine monitor. In a conventional virtual machine monitor, each operating system running within a virtual machine must access the network through a software-virtualized network interface. These virtual network interfaces are multiplexed in software onto a physical network interface, incurring significant performance overheads. The CDNA architecture improves networking efficiency and performance by dividing the tasks of traffic multiplexing, interrupt delivery, and memory protection between hardware and software in a novel way. The virtual machine monitor delivers interrupts and provides protection between virtual machines, while the network interface performs multiplexing of the network data. In effect, the CDNA architecture provides the abstraction that each virtual machine is connected directly to its own network interface. Through the use of CDNA, many of the bottlenecks imposed by software multiplexing can be eliminated without sacrificing protection, producing substantial efficiency improvements
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Concurrent direct network access for virtual machine monitors
Proceedings - International Symposium on High-Performance Computer Architecture, 2007Co-Authors: Paul Willmann, Jeffrey Shafer, Aravind Menon, Alan L. Cox, Scott Rixner, David Carr, Willy ZwaenepoelAbstract:This paper presents hardware and software mechanisms to enable concurrent direct network access (CDNA) by op- erating systems running within a virtual machine monitor In a conventional virtual machine monitor; each operating system running within a virtual machine must access the network through a software-virtualized network interface. These virtual network interfaces are multiplexed in software onto a physical network interface, incurring significant per- formance overheads. The CDNA architecture improves net- working efficiency andperformance by dividing the tasks of traffic multiplexing, interrupt delivery, and memory protec- tion between hardware and software in a novel way. The virtual machine monitor delivers interrupts and provides protection between virtual machines, while the network in- terface performs multiplexing ofthe network data. In effect, the CDNA architecture provides the abstraction that each virtual machine is connected directly to its own network in- terface. Through the use of CDNA, many of the bottlenecks imposed by software multiplexing can be eliminated with- out sacrificing protection, producing substantial efficiency improvements.
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diagnosing performance overheads in the xen virtual machine environment
Virtual Execution Environments, 2005Co-Authors: Aravind Menon, Jose Renato Santos, Yoshio Turner, Gopalakrishnan Janakiraman, Willy ZwaenepoelAbstract:virtual machine (VM) environments (e.g., VMware and Xen) are experiencing a resurgence of interest for diverse uses including server consolidation and shared hosting. An application's performance in a virtual machine environment can differ markedly from its performance in a non-virtualized environment because of interactions with the underlying virtual machine monitor and other virtual machines. However, few tools are currently available to help debug performance problems in virtual machine environments.In this paper, we present Xenoprof, a system-wide statistical profiling toolkit implemented for the Xen virtual machine environment. The toolkit enables coordinated profiling of multiple VMs in a system to obtain the distribution of hardware events such as clock cycles and cache and TLB misses. The toolkit will facilitate a better understanding of performance characteristics of Xen's mechanisms allowing the community to optimize the Xen implementation.We use our toolkit to analyze performance overheads incurred by networking applications running in Xen VMs. We focus on networking applications since virtualizing network I/O devices is relatively expensive. Our experimental results quantify Xen's performance overheads for network I/O device virtualization in uni- and multi-processor systems. With certain Xen configurations, networking workloads in the Xen environment can suffer significant performance degradation. Our results identify the main sources of this overhead which should be the focus of Xen optimization efforts. We also show how our profiling toolkit was used to uncover and resolve performance bugs that we encountered in our experiments which caused unexpected application behavior.
