• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.136-140
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• 2015

Linux environment that is commonly used at embedded systems supports various file systems as Ext2, FAT, NTFS, etc. The file system that is equiped on the embedded system is mostly implemented on mini hard disk or flash memory. The types of the file system of the system make an effect on the performance of a application programs. The factors of file system performance on a same media are block read, block write and block free time. On these factors, block read and block free time are not so different according to the type of file systems. This paper evaluates the performance benchmark of file systems supported by linux about block allocation and write performance. The results obtained from various experiments shows the characteristics of each file system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.355-357
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• 2014

Linux environment that is commonly used at embedded systems, supports various file systems as Ext2, FAT, NTFS, ets. The file system that is equiped on the embedded system is mostly implemented on mini hard disk or flash memory. The types of the file system of the system make an effect on the performance of a application programs. The factors of file system performance on a same media are block allocation and block free time. On these factors, block free time is not so different according to the type of file systems. This thesis performs the performance benchmark of a Ext2, FAT and NTFS file systems about block allocation performance. As the result, it is discussed that what file system is better at which case.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.302-304
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• 2013

The embedded systems on linux environment, commonly equip a file system as mini hard disk or flash memory to keep data. The types of the file system of the system are various according to it's operating system. Anyway, the more embedded system depends on the file system, the selection of the type of the file system effects more on the performance of the system. This thesis performs the performance benchmark of a FAT and Ext file systems. As the result, it is discussed that what file system is better at which case. These results are helpful at the selection of flash file system of the embedded systems on linux environment.

• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.3
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• pp.184-193
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• 2007

Flash memory adoption in the mobile devices is increasing or vanous multimedia services such as audio, videos, and games. Although the traditional research issues such as out-place update, garbage collection, and wear-leveling are important, the performance, memory usage, and fast mount issues of flash memory file system are becoming much more important than ever because flash memory capacity is rapidly increasing. In this paper, we address the problems of the existing log-based flash memory file systems analytically and propose an efficient log-based file system, which produces higher performance, less memory usage and mount time than the existing log-based file systems. Our ideas are applied to a well-known log-based flash memory file system (YAFFS2) and the performance tests are conducted by comparing our prototype with YAFFS2. The experimental results show that our prototype achieves higher performance, less system memory usage, and faster mounting than YAFFS2, which is better than JFFS2.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.1
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• pp.109-114
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• 2014

Recently the operating system share of linux on embedded system is increasing. The embedded systems on linux environment, commonly equip a file system as mini hard disk or flash memory to keep data. The types of the file system of the system are various according to it's operating system. Anyway, the more embedded system depends on the file system, the selection of the type of the file system effects more on the performance of the system. This thesis performs the performance benchmark of a FAT and Ext file systems which are most popular in embedded system. As the result, it is discussed that what file system is better at which case. These results will be a index at the selection of flash file system of the embedded systems on linux environment.

• Journal of the Korea Society of Computer and Information
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• v.22 no.9
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• pp.1-8
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• 2017

In this paper, we propose a file system for flash memory which remedies shortcomings of existing flash memory file systems. Besides supporting large block size, the proposed file system reduces time in initializing file system significantly by adopting logical address comprised of erase block number and bitmap for pages in the block to find a page. The file system is suitable for embedded systems with limited main memory since it has small in-memory data structures. It also provides efficient management of obsolete blocks and free blocks, which contribute to the reduction of file update time. Finally the proposed file system can easily configure the maximum file size and file system size limits, which results in portability to emerging larger flash memories. By conducting performance evaluation studies, we show that the proposed file system can contribute to the performance improvement of embedded systems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.187-189
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• 2012

The embedded systems commonly equip a file system as default to keep data. This file system is mostly constructed with flash memory as the price get lower and the performance get higher. Types of the file system implemented on the flash memory are various according to types of embedded operating systems. By the way, as the embedded systems increasingly depend on the file system, a selection of the file system type of the embedded systems influences the performance of the entire system. This thesis discusses the factors to influence the performance of entire system in construction of file system and selection of the types, and discusses the research results.

• Proceedings of the Korea Contents Association Conference
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• 2004.11a
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• pp.395-401
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• 2004

In the current high network-centralized computing and enterprising environment, it is getting essential to transmit data reliably at very high rates. Until now previous client/server model based NFS(Network File System) or AFS(Andrew's Files System) have met the various demands but from now couldn't satisfy those of the today's scalable high-performance computing environment. Not only performance but data sharing service redundancy have risen as a serious problem. In case of NFS, the locking issue and cache cause file system to reboot and make problem when it is used simply as ip-take over for H/A service. In case of AFS, it provides file sharing redundancy but it is not possible until the storage supporting redundancy and equipments are prepared. Lustre is an open source based cluster file system developed to meet both demands. Lustre consists of three types of subsystems : MDS(Meta-Data Server) which offers the meta-data services, OST(Objec Storage Targets) which provide file I/O, and Lustre Clients which interact with OST and MDS. These subsystems with message exchanging and pursuing scalable high-performance file system service. In this paper, we compare the transmission speed of gigabytes file between Lustre and NFS on the basis of concurrent users and also present the high availability of the file system by removing more than one OST in operation.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.3
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• pp.35-40
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• 2014

Many researches have been conducted to achieve improvement in distributed system that connects multiple computer systems via communication lines. Among others, the load balancing and file migration are considered to have significant impact on the performance of distributed system. The dynamic file migration algorithm common in distributed processing system involved complex calculations of decision function necessary for file migration and required migration of control messages for the performance of decision function. However, the performance of this decision function puts significant computational strain on computer. As one single network is shared by all computers, more computers connected to network means migration of more control messages from file migration, causing the network to trigger bottleneck in distributed processing system. Therefore, it has become imperative to carry out the research that aims to reduce the number of control messages that will be migrated. In this study, the learning automata was used for file migration which would requires only the file reference-related information to determine whether file migration has been made or determine the time and site of file migration, depending on the file conditions, thus reflecting the status of current system well and eliminating the message transfer and additional calculation overhead for file migration. Moreover, mathematical model for file migration was described in order to verify the proposed model. The results from mathematical model and simulation model suggest that the proposed model is well-suited to the distributed system.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.3
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• pp.171-178
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• 2015

Recently NAND flash memory has been found to be the primary cause of low performance in the smart device. NAND flash memory is different from each other the execution time of I/O operations that flash file system is required. Therefore, it is necessary to compare and analyze the flash file system I/O performance for the efficient I/O on smart device. In this paper, it was tested and analyzing the I/O performance of the YAFFS2, JFFS2, UBIFS. Experimental results most read I/O performance is good, but the writing I/O performance is not good. For UBIFS, showed a more good I/O performance compared to other flash file system.