Anti-Aging LFS: Self-Defragmentation With Fragmentation-Aware Cleaning
For several decades, filesystem aging has been widely studied, but nonetheless, it still remains an unsolved problem. Among various filesystems, log-structured filesystems have been reported to be vulnerable to fragmentation due to their append-only write policy. Fragmentation hinders various I/O ac...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
IEEE
2020-01-01
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| Series: | IEEE Access |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/9169877/ |
| _version_ | 1811274246028001280 |
|---|---|
| author | Jonggyu Park Young Ik Eom |
| author_facet | Jonggyu Park Young Ik Eom |
| author_sort | Jonggyu Park |
| collection | DOAJ |
| description | For several decades, filesystem aging has been widely studied, but nonetheless, it still remains an unsolved problem. Among various filesystems, log-structured filesystems have been reported to be vulnerable to fragmentation due to their append-only write policy. Fragmentation hinders various I/O activities such as sequential read and trim operations, regardless of the underlying storage types. This paper extensively analyzes the rationale behind performance degradation incurred by fragmentation on various types of storage devices. To eliminate fragmentation without additional I/O overhead, we propose an anti-aging log-structured filesystem, called AALFS. During segment cleaning, AALFS re-arranges the order of valid blocks based on inode number and file offset to eliminate existing fragmentation. To enhance the efficacy of the re-ordering process, the new victim selection policy of AALFS reflects the fragmentation degree of each segment in the selection of victim segments. Our experimental results show that AALFS effectively eliminates fragmentation by up to 99.8% and significantly improves sequential read performance on various types of storage devices. Particularly, AALFS improves the sequential read throughput of IOzone on hard disk drives by up to 22.8 times. |
| first_indexed | 2024-04-12T23:14:23Z |
| format | Article |
| id | doaj.art-ea32fab062264e70b4833c2491bc3116 |
| institution | Directory Open Access Journal |
| issn | 2169-3536 |
| language | English |
| last_indexed | 2024-04-12T23:14:23Z |
| publishDate | 2020-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Access |
| spelling | doaj.art-ea32fab062264e70b4833c2491bc31162022-12-22T03:12:43ZengIEEEIEEE Access2169-35362020-01-01815147415148610.1109/ACCESS.2020.30172409169877Anti-Aging LFS: Self-Defragmentation With Fragmentation-Aware CleaningJonggyu Park0https://orcid.org/0000-0003-0856-6503Young Ik Eom1https://orcid.org/0000-0001-6141-8054Department of Computer Science and Engineering, Sungkyunkwan University, Suwon, South KoreaDepartment of Electrical and Computer Engineering, College of Computing, Sungkyunkwan University, Suwon, South KoreaFor several decades, filesystem aging has been widely studied, but nonetheless, it still remains an unsolved problem. Among various filesystems, log-structured filesystems have been reported to be vulnerable to fragmentation due to their append-only write policy. Fragmentation hinders various I/O activities such as sequential read and trim operations, regardless of the underlying storage types. This paper extensively analyzes the rationale behind performance degradation incurred by fragmentation on various types of storage devices. To eliminate fragmentation without additional I/O overhead, we propose an anti-aging log-structured filesystem, called AALFS. During segment cleaning, AALFS re-arranges the order of valid blocks based on inode number and file offset to eliminate existing fragmentation. To enhance the efficacy of the re-ordering process, the new victim selection policy of AALFS reflects the fragmentation degree of each segment in the selection of victim segments. Our experimental results show that AALFS effectively eliminates fragmentation by up to 99.8% and significantly improves sequential read performance on various types of storage devices. Particularly, AALFS improves the sequential read throughput of IOzone on hard disk drives by up to 22.8 times.https://ieeexplore.ieee.org/document/9169877/Fragmentationlog-structured filesystemsoperating systemsstorage |
| spellingShingle | Jonggyu Park Young Ik Eom Anti-Aging LFS: Self-Defragmentation With Fragmentation-Aware Cleaning IEEE Access Fragmentation log-structured filesystems operating systems storage |
| title | Anti-Aging LFS: Self-Defragmentation With Fragmentation-Aware Cleaning |
| title_full | Anti-Aging LFS: Self-Defragmentation With Fragmentation-Aware Cleaning |
| title_fullStr | Anti-Aging LFS: Self-Defragmentation With Fragmentation-Aware Cleaning |
| title_full_unstemmed | Anti-Aging LFS: Self-Defragmentation With Fragmentation-Aware Cleaning |
| title_short | Anti-Aging LFS: Self-Defragmentation With Fragmentation-Aware Cleaning |
| title_sort | anti aging lfs self defragmentation with fragmentation aware cleaning |
| topic | Fragmentation log-structured filesystems operating systems storage |
| url | https://ieeexplore.ieee.org/document/9169877/ |
| work_keys_str_mv | AT jonggyupark antiaginglfsselfdefragmentationwithfragmentationawarecleaning AT youngikeom antiaginglfsselfdefragmentationwithfragmentationawarecleaning |