Search 250 million research papers

Dynamic Party System Fragmentation - Replication File

Thiago Moreira, Jose Antonio Cheibub, Gisela Sin et al. · OSF Preprints (OSF Preprints)

Cited by 0

Dynamic Party System Fragmentation - Replication File

Gisela Sin, Keigo Tanabe, Thiago M. Q. Moreira et al. · OSF Preprints (OSF Preprints) · 2023

Cited by 0

File System Aging: A Study of Fragmentation in ZFS

Tommaso Monaco (14102394) · Figshare · 2020

Fragmentation in ZFS is an understudied concept. Fragmentation is a side effect of the file allocation strategies of a file system, which have to store files on disk without knowing whether the file will grow or be deleted in the future. Although negative effects of fragmentation are often understated, recent research suggests that fragmentation leads to severe suboptimal system performance. \n This paper describes consistent and synthetic workloads that can induce fragmentation in ZFS for research purposes. This provides proof that ZFS is prone to fragmentation under specific workloads. It also offers a way for researchers to quickly reproduce a file system with fragmentation so that its effects on ZFS can be further examined. My work represents early steps in a study of fragmentation-related research and the development of defragmentation tools in ZFS.

Cited by 0Open access

FragTracer: Real-Time Fragmentation Monitoring Tool for F2FS File System

Minseon Cho, Dong Hyun Kang · Sensors · 2023

Emerging hardware devices (e.g., NVMe SSD, RISC-V, etc.) open new opportunities for improving the overall performance of computer systems. In addition, the applications try to fully utilize hardware resources to keep up with those improvements. However, these trends can cause significant file system overheads (i.e., fragmentation issues). In this paper, we first study the reason for the fragmentation issues on an F2FS file system and present a new tool, called FragTracer, which helps to analyze the ratio of fragmentation in real-time. For user-friendly usage, we designed FragTracer with three main modules, monitoring, pre-processing, and visualization, which automatically runs without any user intervention. We also optimized FragTracer in terms of performance to hide its overhead in tracking and analyzing fragmentation issues on-the-fly. We evaluated FragTracer with three real-world databases on the F2FS file system, so as to study the fragmentation characteristics caused by databases, and we compared the overhead of FragTracer. Our evaluation results clearly show that the overhead of FragTracer is negligible when running on commodity computing environments.

Cited by 1Open access

Fragmentation-Less FAT-compatible File System for Internet of Things

Haecheon Kim, Dongwoo Kang, Kwanghee Lee et al. · 2018

In this paper, we propose a new file system, called FL-FAT, for IoT (Internet of Things) devices. By considering the data manipulating characteristics in IoT devices, FL-FAT employs two techniques, partitioning and pre-allocation so that it can reduce internal fragmentation. Also, it devises a novel space reclaiming technique that frees the unused pre-allocated space while supporting FAT-compatibility. We have implemented FL-FAT in the Android platform on ARM-based experimental board. Performance evaluation results show that our file system can eliminate fragmentation, which enables to improve performance by up to 22%.

Cited by 1

Countering Fragmentation in an Enterprise Storage System

Ram Kesavan, Matthew Curtis-Maury, Vinay Devadas et al. · ACM Transactions on Storage · 2019

As a file system ages, it can experience multiple forms of fragmentation. Fragmentation of the free space in the file system can lower write performance and subsequent read performance. Client operations as well as internal operations, such as deduplication, can fragment the layout of an individual file, which also impacts file read performance. File systems that allow sub-block granular addressing can gather intra-block fragmentation, which leads to wasted free space. Similarly, wasted space can also occur when a file system writes a collection of blocks out to object storage as a single large object, because the constituent blocks can become free at different times. The impact of fragmentation also depends on the underlying storage media. This article studies each form of fragmentation in the NetApp ® WAFL ® file system, and explains how the file system leverages a storage virtualization layer for defragmentation techniques that physically relocate blocks efficiently, including those in read-only snapshots. The article analyzes the effectiveness of these techniques at reducing fragmentation and improving overall performance across various storage media.

Cited by 5

Extended Abstract

Hyun-chan Park, Jun-seok Lee, Chuck Yoo · 2015

The fragmentation is a traditional problem of file system. Currently, it is much more important problem because of that the difference between CPU and I/O performance was increased. When a fragmentation occurs, file system cannot maintain its own block allocation policy and block layout on disk. For these reasons, the

Cited by 0

File Fragmentation in Mobile Devices: Measurement, Evaluation, and Treatment

Cheng Ji, Li-Pin Chang, Sangwook Shane Hahn et al. · IEEE Transactions on Mobile Computing · 2018

Mobile devices, such as smartphones, have become a necessity in our daily life. However, users may notice that after being used for a longtime, mobile devices begin to exhibit a sluggish response. Based on an empirical study on a collection of aged smartphones, this work identified that file fragmentation is among the key factors that contribute to the progressive degradation of response time. This study takes a three-step approach: First, this study designed a set of reproducible file-system aging processes based on User-Interface (UI) script replay. Through the aging processes, it confirmed that file fragmentation quickly emerged, and SQLite files were among the most severely fragmented files. Second, based on the workloads of a selection of popular mobile applications, this study observed that file fragmentation did have an impact on user-perceived latencies. Specifically, the launching time of Chrome on an aged file system was 79 percent slower than it was on a pristine file system. Third, this study evaluated existing treatments of file fragmentation, including space preallocation, persistent journal, and file defragmentation to understand their efficacies and limitations. This study also evaluated a state-of-the-art copyless defragmenter, janusd, to show its advantage over the existing methods.

Cited by 20

Master File System (MFS): A New Paradigm for Hierarchical Multi-User Storage

Aliakbar Kavosi · Zenodo (CERN European Organization for Nuclear Research) · 2026

Master File System (MFS) is a revolutionary file system architecture designed to address fundamental limitations of existing storage systems. MFS provides 10x longer SSD lifetime, instant file copy/move, built-in undelete, and zero fragmentation by design. Author: Aliakbar KavosiDate: February 12, 2026License: CC BY-NC-ND 4.0

Cited by 0Open access

Master File System (MFS): A New Paradigm for Hierarchical Multi-User Storage

Aliakbar Kavosi · Zenodo (CERN European Organization for Nuclear Research) · 2026

Master File System (MFS) is a revolutionary file system architecture designed to address fundamental limitations of existing storage systems. MFS provides 10x longer SSD lifetime, instant file copy/move, built-in undelete, and zero fragmentation by design. Author: Aliakbar KavosiDate: February 12, 2026License: CC BY-NC-ND 4.0

Cited by 0Open access

Display list generation benchmark results.

Michael Riss (551517) · Figshare · 2015

<p>Results of the OpenGL display list generation benchmarks for time series, event and interval data, showing the influence of tuning parameters, file system cache, and file system fragmentation. See main text for detailed discussion.</p>

Cited by 0Open access

Additional file 1 of Sleep fragmentation affects glymphatic system through the different expression of AQP4 in wild type and 5xFAD mouse models

Vasciaveo, Valeria, Iadarola, Antonella, Casile, Antonino et al. · Figshare · 2024

Additional file 1. Table S1. Differences in EPM data analyses between not fragmented (NF) and fragmented (F) animals before the beginning of the protocol. Table S2. Differences in OF data analyses between not fragmented (NF) and fragmented (F) animals before the beginning of the protocol. Table S3. Differences in NOR data analyses between not fragmented (NF) and fragmented (F) animals before the beginning of the protocol. Table S4. Differences in Y-maze data analyses between not fragmented (NF) and fragmented (F) animals before the beginning of the protocol. Fig. S1. AQP4 and its isoform expression. Fig. S2. AQP4 and GFAP colocalization analysis.

Cited by 0Open access

Additional file 1 of Sleep fragmentation affects glymphatic system through the different expression of AQP4 in wild type and 5xFAD mouse models

Vasciaveo, Valeria, Iadarola, Antonella, Casile, Antonino et al. · Figshare · 2024

Additional file 1. Table S1. Differences in EPM data analyses between not fragmented (NF) and fragmented (F) animals before the beginning of the protocol. Table S2. Differences in OF data analyses between not fragmented (NF) and fragmented (F) animals before the beginning of the protocol. Table S3. Differences in NOR data analyses between not fragmented (NF) and fragmented (F) animals before the beginning of the protocol. Table S4. Differences in Y-maze data analyses between not fragmented (NF) and fragmented (F) animals before the beginning of the protocol. Fig. S1. AQP4 and its isoform expression. Fig. S2. AQP4 and GFAP colocalization analysis.

Cited by 0Open access

A High-Performance Distributed File System for Mass Data

Shuaiyu Jin, Qing Yan, Yue Zhang et al. · 2020

With the rapid development of the mobile Internet and cloud computing, storage sub system's pressure increasing fast as the critical process needs more powerful engines. The paper realizes a high-performance distributed file system based on raft protocol. Our file system guarantees the reliability of data through replication. Write-Ahead Logging (WAL) and raft consensus algorithm provide atomicity, durability and file distribution. In order to solve the problem of data fragmentation in distributed systems, we design an automatic fragmentation and load balancing mechanism based on consistent hashing. Each file goes through the raft state machine so that a few machines crash without I/O error. We also implement the FUSE interface for the users to mount and work on files. Performance measurements under some typical workloads show that our file system has excellent I/O performance.

Cited by 1

Multi-Carrier Steganographic Algorithm Using File Fragmentation of FAT FS

Liberios Vokorokos, Branislav Madoš, Norbert Ádám et al. · Computing and Informatics · 2019

Steganography is considered to be not only a science, but also a craft of concealing ongoing communication by hiding messages in unsuspicious cover documents, such as texts, digital images, audio and video sequences. Its essential feature is the constant search for - often exceptionally creative - possibilities of concealing information. In computers, steganography often uses secondary memory and exchangeable memory media utilising file systems. This paper deals with the current state of the issues related to information hiding by means of hard disks, being the most important source of forensic data. This paper focuses on information hiding using the File Allocation Table (FAT) file system. It also proposes a novel multi-carrier algorithm of hiding information in file fragmentation. The algorithm provides flexibility of encoding the information to be hidden and makes steps toward optimization that allows reduction of interference with the current state of the file system, represented by the statistical values of the file fragmentation parameters.

Cited by 5Open access

NON-SYMBOLIC FRAGMENTATION CRYPTOGRAPHIC ALGORITHMS

Coupe, Henry David James · OpenGrey (Institut de l'Information Scientifique et Technique) · 2005

Non-symbolic fragmentation is an existing method for securing data. It has benefits over conventional cryptography and, due to its relative simplicity, can be made to execute very quickly. Fragmentation (in this research) refers to the breaking up of data into fragments of random length, followed by the sequential allocation of each of these fragments to one of a number of streams. This is called non-symbolic fragmentation when the fragment sizes are not necessarily a whole number of bytes in length and subsymbolic fragmentation if all of the fragment sizes are less than 8 bits in length. If a file is sub-symbolically fragmented then, as long as no two consecutive fragments are allocated to the same stream, each byte in the original file will not exist entirely within any one stream after fragmentation. If these streams are then sent over an unsecured network, anyone intercepting any one of these streams will not have obtained a single whole byte of the original data. Alternatively, if the streams are appended to one another to form a new file, the bits of each byte in the original file will not exist together at any single place in the new file. Non-symbolic fragmentation is currently under patent [GA01] and hence is a potentially commercial encryption system. The contributions of this thesis are: 1) The analysis of different variants of non-symbolic fragmentation, in terms of security and algorithm efficiency. 2) A comparison of the level of security provided, when compared to existing established cryptographic methods. 3) The refinement and expansion of existing prototype algorithms that have already been implemented using non-symbolic fragmentation. 4) The development of tools that measure the relative merits of non-symbolic fragmentation algorithms. In particular, a method is developed that relates the underlying non-symbolic fragmentation process to the research that has been done into the mathematics of card shuffling. Acknowledgements I would like to thank my supervisor Helen Ashman, my sponsor Amino

Cited by 0

A comparison of FFS disk allocation policies

Keith A. Smith, Margo Seltzer · 1996

A new disk allocation algorithm, added to a recent version of the UNIX Fast File System, attempts to improve file layout by exploiting the clusters of free space that are available in the file system. In this paper I study the effectiveness of this algorithm at reducing file system fragmentation. To do this, I have created a program that artificially ages a file system by replaying a workload similar to that experienced by a real file system. To evaluate the effectiveness of the new disk allocation algorithm, I use this program to replay four months of activity on two file systems that differ only in the disk allocation algorithms that they use. At the end of the four month simulation, the file system that used the new allocation algorithm had 3 % more file data blocks that were contiguously laid out. 1

Cited by 48

Testing a file carving tool using realistic datasets generated with openness by a user level file system

K. Srinivas, T. Venugopal · International Journal of Data Analysis Techniques and Strategies · 2020

During the development phase of a file carver, it is inappropriate to use a used hard disk as an input medium due to the fact that the file system does not provide openness regarding file fragmentation and location of data on the disk. In this paper, we propose a method that provides realistic datasets with openness which can be used to test carving tools. Realistic property of datasets is achieved by implementing a file system at user level. A large file is used to mimic a hard disk in this process. The large file, on the hard disk, is handled by the host file system. The same large file to mimic as a test hard disk is handled by a file system at user level and hence openness is achieved.

Cited by 2

Comparative analysis and study of the properties of information carriers for steganographic data hiding in clustered file sys-tems

Kyryl Shekhanin, Ludmila Gorbachova, Kuznetsova Kuznetsova · Computer Science and Cybersecurity · 2021

The paper studies and analyzes various modern information storage technologies, namely HDD, Flash-USB, SSD. We`ve analyzed different indicators such as the number of implemented products, price, speed of reading and writing. Besides, we`ve considered some indicators of the information carriers’ efficiency in terms of view of the possibility of using steganographic methods for hiding information in clustered file systems. It have been analyzed the speed of sequential reading / writing and the speed of access to a random cluster, corresponding to the speed of access to a fragmented file. For this task, we used the test results from the UserBenchmark resource. The testing has made using the Sequential and Random4k methods. In addition, we have provided an assessment of information carriers and have gave recommendations of using the particular information carrier and method for hiding data by mixing clusters in the structure of the file system. Besides, it was analyzed the dependence of the speed parameters of access to the cluster on the level of file fragmentation. Refinements are made of how an increase or decrease in the level of fragmentation (entanglement) affects the speed of access to the file, which is an important indicator when using the method of hiding data in the file system structure. The advantages and disadvantages of various types of storage devices have been discussed, and its comparative analysis was made. Moreover, we analyzed the features of the process of defragmentation of drives, and the influence of various factors on the overall level of fragmentation on the storage medium. We placed emphasis on the greater the level of fragmentation on the storage medium, the more information could be hidden. It was concluded that due to the widespread use of SSD / HDD drives, the method of hiding information in the structure of file systems, by mixing clusters of covering files, is relevant.

Cited by 0

conduit flow simulation results

Katherine R Coppess · OSF Preprints (OSF Preprints) · 2022

The data file naming system is as follows: {fragmentation sharpness, k}__RUPTURE__{total eruption time}s_{# grid points}pts__CHAM_{chamber volume modulo 1e6m^3}m3__PLUG_{plug amplitude}Pa_{plug width}_pos{plug position}m__MAGMA_cVF{critical gas volume percentage}_n{total volatile mass percentage}.{mat or zip} The stored dictionary for .mat file is {'depths', 'time', 'conduit-pressure', 'velocity', 'mass-fraction', 'density', 'shear-traction-on-earth', 'chamber-pressure'}.

Cited by 0