• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8C
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• pp.670-679
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• 2012

The recent dissemination of cloud computing makes the amount of data storage to be increased and the cost of storing the data grow rapidly. Accordingly, data and service requests from users also increases the load on the cloud storage. There have been many works that tries to provide low-cost and high-performance schemes on distributed file systems. However, most of them have some weaknesses on performing parallel and random data accesses as well as data accesses of frequent small workloads. Recently, improving the performance of distributed file system based on caching technology is getting much attention. In this paper, we propose a CHPC(Cloud storage High-Performance Caching) framework, providing parallel caching, distributed caching, and proxy caching in distributed file systems. This study compares the proposed framework with existing cloud systems in regard to the reduction of the server's disk I/O, prevention of the server-side bottleneck, deduplication of the page caches in each client, and improvement of overall IOPS. As a results, we show some optimization possibilities on the cloud storage systems based on some evaluations and comparisons with other conventional methods.

• Journal of Digital Contents Society
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• v.15 no.3
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• pp.395-403
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• 2014

Recently webhard services in various applications have been notably increased. In order to adopt some webhard functions into the existing application platform, however, a lot of manpower and cost is necessary. In this paper, we propose webhard API based on cloud storage for building and extending the webhard functions. The proposed system consists of three layers: application, web-hard server, and storage server in which each layer provides its API independently. It is enable the developer to easily extend the webhard functions to the application by using only HTTP request, which provides no limitation of the programming language. Because our webhard API is running on the virtualized cloud storage, it is possible to easily extend the storages and to reduce the maintenance cost. In this paper, we implement all the webhard API and then show the result of adopting the API to a prototype groupware system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.305-311
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• 2010

iATA (Internet Advanced Technology Attachment) is a block-level protocol developed to transfer ATA commands over TCP/IP network, as an alternative network storage solution to address insufficient storage problem in mobile devices. This paper employs RAID5 distributed storage servers concept into iATA, in which the idea behind is to combine several machines with relatively inexpensive disk drives into a server array that works as a single virtual storage device, thus increasing the reliability and speed of operations. In the case of one machine failed, the server array will not destroy immediately but able to function in a degradation mode. Meanwhile, information can be easily recovered by using boolean exclusive OR (XOR) logical function with the bit information on the remaining machines. We perform I/O measurement and benchmark tool result indicates that additional fault tolerance feature does not delay read/write operations with reasonable file size ranged in 4KB-2MB, yet higher data integrity objective is achieved.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1145-1152
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• 2021

In order to optimize the performance of 1.4P large storage, the characteristics of each chunk mode were investigated, and the chunk 512K mode was selected in terms of I/O speed. NVME storage system was configured and used to measure data server performance of large storage. By measuring the change in throughput according to the number of threads of the 1.4P large storage, the characteristics of the large storage system were identified, and it was confirmed that the performance was up to 133Gbps with a block size of 32KB. As a result of data transmission/reception experiment using globus-url-copy of GridFTP, it was found that this large storage has a throughput of 33Gbps.

• Journal of Digital Convergence
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• v.12 no.9
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• pp.153-158
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• 2014

The Collaborative Cloud Storage is that several members of collaborating group together use data stored in a storage. Therefore, it is obvious that it is more complicated and important to protect data stored in the sharing storage than general cloud storage, not Collaborative Cloud Storage. this paper proposes a method for user authentication and data protection.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.923-926
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• 2003

iSCSI(Internet Small Computer Systems Interface)프로토콜은 TCP/IP 네트워크를 통해 블록 중심형 스토리지 데이터에 접근을 가능하게 하는 SCSI 전송프로토콜이다. iSCSI는 서버에서 스토리지장치로의 데이터 전송을 위해 표준 이더넷 스위치와 라우터를 사용하며, 또한 기존의 IP 네트워크를 사용하여 SAN 의 확장이 가능하다. 본 논문에서는 이러한 iSCSI 를 사용하여 여러가지 다른 환경에서 iSCSI 프로토콜의 성능을 분석한다. 첫째는 스토리지 장치에 따른 iSCSI 의 성능변화와 둘째는 현재의 네트웍 망에서의 변화이다. 이더넷에서 스토리지 데이터를 액세스하는데 있어서 시급했던 문제중에 하나는 충분한 대역폭과 낮은 지연율을 제공하는 것이었다. 최근의 이더넷 기술의 발전은 IP 네트워크를 통해 스토리지 장치를 액세스하는 것이 가능해졌으며 백본망을 비롯한 기가비트 이더넷이 활성화된 오늘날의 네트워크 망에서 iSCSI를 이용한 스토리지 서비스가 활성화 될 것이다. 본 논문에서는 iSCSI의 기반이 되는 IP네트워크에서의 iSCSI의 성능을 분석한 내용을 기술한다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.1
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• pp.155-164
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• 2015

Information dispersal algorithm guarantees high availability and confidentiality for data and is one of the useful solutions for faulty and untrusted dispersed storage systems such as cloud storages. As the amount of data stored in storage systems increases, data deduplication which allows to save IT resources is now being considered as the most promising technology. Hence, it is necessary to study on an information dispersal algorithm that supports data deduplication. In this paper, we propose an information dispersal algorithm and proof of ownership for client-side data deduplication in the dispersed storage systems. The proposed solutions allow to save the network bandwidth as well as the storage space while giving robust security guarantee against untrusted storage servers and malicious clients.

• KIISE Transactions on Computing Practices
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• v.21 no.1
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• pp.58-63
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• 2015

In this work, we present a novel fountain code-based hybrid P2P storage system that combines cloud storage with P2P storage. The proposed hybrid storage system minimizes data transmission time while guaranteeing high data retrieval and data privacy. In order to guarantee data privacy and storage efficiency, the user transmits encoded data after performing fountain code-based encoding. Also, the proposed algorithm guarantees the user's data retrieval by storing the data while considering each peer's survival probability. The simulation results show that the proposed algorithm enables fast completion of the upload transmission while satisfying the required data retrieval and supporting the privacy of user data under the system parameters.

• Journal of Internet Computing and Services
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• v.17 no.3
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• pp.55-66
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• 2016

A local storage of HTML5 is a Web Storage, which is stored permanently on a local computer in the form of files. The contents of the storage can be easily accessed and modified because it is stored as plaintext. Moreover, because the internet browser classifies the local storages of each domain using file names, the malicious attacker can abuse victim's local storage files by changing file names. In the paper, we propose a scheme to maintain the integrity and the confidentiality of the local storage's source domain and source device. The key idea is that the client encrypts the data stored in the local storage with cipher key, which is managed by the web server. On the step of requesting the cipher key, the web server authenticates whether the client is legal source of local storage or not. Finally, we showed that our method can detect an abnormal access to the local storage through experiments according to the proposed method.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.802-804
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• 2005

유비쿼터스 환경에 대한 관심과 휴대용 컴퓨팅 기기의 보급으로 가까운 미래의 사람들은 언제 어디서나 네트워크를 통해 데이터 접근이 가능하게 될 것이다. 특히 영화나 음악과 같은 멀티미디어 데이터의 폭발적인 증가로 인해 확장성 있는 네트워크 스토리지 시스템의 필요성이 부각되고 있다. SAN(Storage Area Network)은 높은 확장성과 빠른 속도를 제공하여 엔터프라이즈 환경에 적합한 스토리지 네트워크 시스템이다. 최근에 SAN 환경은 SCSI Architecture Model(SAM)의 표준으로 채택된 iSCSI를 이용한 IP기반의 SAN으로 옳겨가고 있다. 본 논문에서는 iSCSI 기반의 IP SAN환경에서 서비스 클라이언트가 증가함에 따라 스토리지 서버의 부하가 커지는 문제를 해결하기 위해 스토리지 디바이스에서 클라이언트로 데이터를 직접 전송하는 방안을 제안한다.