• Communications of the Korean Institute of Information Scientists and Engineers
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• v.34 no.7
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• pp.45-50
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• 2016

• 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 Internet of Things and Convergence
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• v.10 no.5
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• pp.133-138
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• 2024

SSD SSD are rapidly replacing HDD as the storage device of choice for modern computer systems due to their high speed and reliability. Since these SSD are used in large quantities in enterprise environments, the LED blinking method is used to check the status of each SSD. This method controls the blinking rate of the LEDs based on the behavior and status of the SSD. The traditional method of using LED in SSD simply controls the blinking speed and time of the LED to indicate power on, data transfer, error, etc. However, in recent years, various studies have been conducted to transmit data using the color and blinking of LED. In this paper, we propose a new communication method that uses the LED blinking of SSD to transmit signals according to a certain rule. In the proposed method, the signals are classified into numeric and character systems according to the duration of the on LED signal, and various information systems are designed by combining the classified signals. In addition, a protocol is designed to transmit these combined signals, and a method is designed to display the transmitted signals in an intuitively identifiable representation at the receiving end of the enclosure. This approach is expected to free up additional communication channels of existing SSD and increase the performance and efficiency of the system.