• Journal of KIISE
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• v.43 no.1
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• pp.27-33
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• 2016

Virtualization has become one of the most helpful techniques in computing systems, and today it is prevalent in several computing environments including desktops, data-centers, and enterprises. However, since I/O layers are implemented to be oblivious to the I/O behaviors on virtual machines (VM), there still exists an I/O scalability issue in virtualized systems. In particular, when a multi-queue solid state drive (SSD) is used as a secondary storage, each system reveals a semantic gap that degrades the overall performance of the VM. This is due to two key problems, accelerated lock contentions and the I/O parallelism issue. In this paper, we propose a novel approach, including the design of virtual CPU (vCPU)-dedicated queues and I/O threads, which efficiently distributes the lock contentions and addresses the parallelism issue of Virtio-blk-data-plane in virtualized environments. Our approach is based on the above principle, which allocates a dedicated queue and an I/O thread for each vCPU to reduce the semantic gap. Our experimental results with various I/O traces clearly show that our design improves the I/O operations per second (IOPS) in virtualized environments by up to 155% over existing QEMU-based systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.482-488
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• 2012

Desktop is offered to each individual in Educational environments of school or academy, as the users are increasing, the more Desktop is required for each person. Huge Desktop accession resulted in many problems including difficulty of management, Software and Hardware cost rising, cramped places, power consumption increasing and etc. To solve those problems, we focus into uprising technology solution, such as Multi Computer, Desktop Virtualization, and DaaS(Desktop as a Service). In this paper, existing problems that can dramatically improve the private cloud computing for desktop virtualization with the requirements of the system were analyzed.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.6
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• pp.1355-1362
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• 2012

As the utilization of cloud computing service rapidly increases to meet demands for various forms of service recently, the virtualization technology has made a rapid rise, further leading to some issues related to security, such as safety and reliability. As a system to provide environments what multiple virtual operating systems can be loaded, hypervisors may be a target of various attacks, such as control loss and authority seizure, since all the agents fcan be damaged by a malicious access to the virtualization layer. Therefore, this paper was conducted to investigate the access control for agents and suggest a plan to control malicious accesses to the cloud virtualization internal environment. The suggested technique was verified not to have effect on the performance of the system and environment through an analysis of its performance.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.5
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• pp.123-136
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• 2021

RPC (Remote Procedure Call)-based Graphics Processing Unit (GPU) virtualization technology is one of the technologies for sharing GPUs with multiple user virtual machines. However, in a cloud environment, unlike CPU or memory, general GPUs do not provide a resource isolation technology that can limit the resource usage of virtual machines. In particular, in an RPC-based virtualization environment, since GPU tasks executed in each virtual machine are performed in the form of multi-process, the lack of resource isolation technology causes performance degradation due to resource competition. In addition, the GPU memory competition accelerates the performance degradation as the resource demand of the virtual machines increases, and the fairness decreases because it cannot guarantee equal performance between virtual machines. This paper, in the RPC-based GPU virtualization environment, analyzes the performance degradation problem caused by resource contention when the GPU memory requirement of virtual machines exceeds the available GPU memory capacity and proposes a GPU memory management technique to solve this problem. Also, experiments show that the GPU memory management technique proposed in this paper can improve the performance of GPGPU tasks.

• Convergence Security Journal
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• v.23 no.4
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• pp.23-32
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• 2023

Container-based virtualization has attracted many attentions as an alternative to virtual machine technology because it can be used more lightly by sharing the host operating system instead of individual guest operating systems. However, this advantage may owe some vulnerabilities. In particular, excessive resource use of some containers can affect other containers, which is known as the noisy neighbor problem, so that the important property of isolation may not be guaranteed. The noisy neighbor problem can threat the availability of containers, so we need to consider the noisy neighbor problem as a security problem. In this paper, we investigate vulnerabilities on guarantee of isolation incurred by the noisy neighbor problem in container-based virtualization. For this we first analyze the structure of container-based virtualization environments. Then we present vulnerabilities in 3 functional layers and general directions for solutions with limitations.

• The Journal of Korean Association of Computer Education
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• v.18 no.2
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• pp.83-90
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• 2015

In an virtualization environment, several virtual machines use physical resources together. If a specific virtual machine uses to much of the computing resources, other machines may not be working properly. There are various method to solve this problem. Most representative study is to migrate a specified virtual machines to a different server, a target server. In this study, server load can be transferred to a target server by the remigrate of the load imposed on virtual machine. It is still problematic that virtual machine has to remigrate to a different server. This thesis has proposed the algorithm determining the remigration targets by applying dynamic thresholds to solve those problems. The migration algorithm applies dynamic thresholds according to the following criteria. Firstly, the usage of CPU, network and memory; secondly, decide the set of artificial machine and the target server based on the resources surpassed thresholds; thirdly, determine artificial machines based on the resource usage in the target server.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.1
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• pp.117-124
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• 2016

Virtual environment is widely used for analyzing malware which is increasing very rapidly. However, knowing this trend, hackers are adopting virtual environment detection techniques for malware to kill itself or stop malicious behaviors when detecting virtual environments. Various research is going on in order to thwart any efforts to utilize anti-virtualization techniques, but until now several techniques can evade most of well known virtual environments, making malware analysis very difficult. Emulab developed by Utah University assigns real systems and networks as researchers want in realtime. This research seeks how to use Emulab for malware analysis.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.103-112
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• 2009

This paper proposes an efficient storage virtualization system which allows users to view hard disk resources of numerous nodes as a large logical space using distributed hash tables of P2P techniques. The proposed system is developed at device level of Windows operating system and is suitable for users in Intranet environments. This system is developed to be recognized as one hard disk at the Windows explorer for user conveniences and does not need a supplementary client program at the application layer. In addition, it enhances security via cutting off breaches from external networks.

• Journal of Korea Multimedia Society
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• v.17 no.3
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• pp.353-363
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• 2014

Cloud computing is an internet-based technology, providing services to the virtualized IT environment, and allowing users to add or remove resources of hardware or software at their discretion. Since Cloud computing can construct virtually integrated environments out of multiple local computing environments, various information services can be provided by it. In addition, state organizations also strive to build the cloud computing environments due to the benefits of reduced costs to introduce the system and of reduced time to build and provide the IT services. This study suggests a web-based cloud computing system for the computing environments, to be applied for the Korean National Health and Nutrition Examination Survey (KNHANES) by the Ministry of Health and Welfare, Republic of Korea.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.178-180
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• 2017

Virtualization was devised as a resource management and optimization technique for mainframes having scaleless computing capabilities. The resource scaling can be done with a variety of virtualization methods such as VM creation, deletion, and migration. In this paper, we designed to achieve the load balancing, several load balancing schemes such as Minimum Execution Time (MET), Min-Min scheduling, Cloud Analyst have been reported in literature in addition to a comprehensive study on First Come First Serve (FCFS) and Round-robin schedulers.