요약·해설과 원문, 전문 번역을 서로 분리했습니다. API 이름, symbol, source path는 원문 표기를 사용합니다.
1. 요약·해설
원문의 핵심 논리와 kernel programming 관점의 보충 설명입니다. 아래의 전문 번역과는 별도로 작성했습니다.
Features, accounting and I/O flags
sysfs-fs-f2fs:243-503On-disk·kernel feature discovery, urgent GC, filesystem counters, temperature-based I/O flags와 live superblock·checkpoint status를 제공합니다.
Compression, ATGC and atomic writes
sysfs-fs-f2fs:504-683Discard statistics, checkpoint daemon priority, compression savings, ATGC victim controls, fragmented allocation과 atomic-write counters를 설명합니다.
Fault injection, zoned storage and multi-device policy
sysfs-fs-f2fs:684-935Data-age separation, comprehensive fault-injection bitmasks, compression cache limits, zoned GC·allocation과 multi-device write priority를 다룹니다.
2. 영어 원문 전체
번역 기준이 된 Linux v6.18.37 원문입니다. 줄 번호는 이 버전의 파일 좌표입니다.
원문 전체 펼치기
1
What: /sys/fs/f2fs/<disk>/gc_max_sleep_time
2
Date: July 2013
3
Contact: "Namjae Jeon" <[email protected]>
4
Description: Controls the maximum sleep time for gc_thread. Time
5
is in milliseconds.
7
What: /sys/fs/f2fs/<disk>/gc_min_sleep_time
8
Date: July 2013
9
Contact: "Namjae Jeon" <[email protected]>
10
Description: Controls the minimum sleep time for gc_thread. Time
11
is in milliseconds.
13
What: /sys/fs/f2fs/<disk>/gc_no_gc_sleep_time
14
Date: July 2013
15
Contact: "Namjae Jeon" <[email protected]>
16
Description: Controls the default sleep time for gc_thread. Time
17
is in milliseconds.
19
What: /sys/fs/f2fs/<disk>/gc_idle
20
Date: July 2013
21
Contact: "Namjae Jeon" <[email protected]>
22
Description: Controls the victim selection policy for garbage collection.
23
Setting gc_idle = 0(default) will disable this option. Setting:
25
=========== ===============================================
26
gc_idle = 1 will select the Cost Benefit approach & setting
27
gc_idle = 2 will select the greedy approach & setting
28
gc_idle = 3 will select the age-threshold based approach.
29
=========== ===============================================
31
What: /sys/fs/f2fs/<disk>/reclaim_segments
32
Date: October 2013
33
Contact: "Jaegeuk Kim" <[email protected]>
34
Description: This parameter controls the number of prefree segments to be
35
reclaimed. If the number of prefree segments is larger than
36
the number of segments in the proportion to the percentage
37
over total volume size, f2fs tries to conduct checkpoint to
38
reclaim the prefree segments to free segments.
39
By default, 5% over total # of segments.
41
What: /sys/fs/f2fs/<disk>/main_blkaddr
42
Date: November 2019
43
Contact: "Ramon Pantin" <[email protected]>
44
Description: Shows first block address of MAIN area.
46
What: /sys/fs/f2fs/<disk>/ipu_policy
47
Date: November 2013
48
Contact: "Jaegeuk Kim" <[email protected]>
49
Description: Controls the in-place-update policy.
50
updates in f2fs. User can set:
52
===== =============== ===================================================
53
value policy description
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0x00 DISABLE disable IPU(=default option in LFS mode)
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0x01 FORCE all the time
56
0x02 SSR if SSR mode is activated
57
0x04 UTIL if FS utilization is over threshold
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0x08 SSR_UTIL if SSR mode is activated and FS utilization is over
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threshold
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0x10 FSYNC activated in fsync path only for high performance
61
flash storages. IPU will be triggered only if the
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# of dirty pages over min_fsync_blocks.
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(=default option)
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0x20 ASYNC do IPU given by asynchronous write requests
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0x40 NOCACHE disable IPU bio cache
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0x80 HONOR_OPU_WRITE use OPU write prior to IPU write if inode has
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FI_OPU_WRITE flag
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===== =============== ===================================================
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Refer segment.h for details.
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What: /sys/fs/f2fs/<disk>/min_ipu_util
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Date: November 2013
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Controls the FS utilization condition for the in-place-update
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policies. It is used by F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies.
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What: /sys/fs/f2fs/<disk>/min_fsync_blocks
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Date: September 2014
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Controls the dirty page count condition for the in-place-update
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policies.
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What: /sys/fs/f2fs/<disk>/min_seq_blocks
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Date: August 2018
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Controls the dirty page count condition for batched sequential
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writes in writepages.
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What: /sys/fs/f2fs/<disk>/min_hot_blocks
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Date: March 2017
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Controls the dirty page count condition for redefining hot data.
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What: /sys/fs/f2fs/<disk>/min_ssr_sections
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Date: October 2017
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Contact: "Chao Yu" <[email protected]>
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Description: Controls the free section threshold to trigger SSR allocation.
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If this is large, SSR mode will be enabled early.
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What: /sys/fs/f2fs/<disk>/max_small_discards
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Date: November 2013
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Controls the issue rate of discard commands that consist of small
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blocks less than 2MB. The candidates to be discarded are cached during
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checkpoint, and issued by issue_discard thread after checkpoint.
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It is enabled by default.
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What: /sys/fs/f2fs/<disk>/max_ordered_discard
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Date: October 2022
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Contact: "Yangtao Li" <[email protected]>
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Description: Controls the maximum ordered discard, the unit size is one block(4KB).
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Set it to 16 by default.
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What: /sys/fs/f2fs/<disk>/max_discard_request
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Date: December 2021
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Contact: "Konstantin Vyshetsky" <[email protected]>
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Description: Controls the number of discards a thread will issue at a time.
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Higher number will allow the discard thread to finish its work
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faster, at the cost of higher latency for incoming I/O.
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What: /sys/fs/f2fs/<disk>/min_discard_issue_time
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Date: December 2021
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Contact: "Konstantin Vyshetsky" <[email protected]>
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Description: Controls the interval the discard thread will wait between
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issuing discard requests when there are discards to be issued and
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no I/O aware interruptions occur.
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What: /sys/fs/f2fs/<disk>/mid_discard_issue_time
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Date: December 2021
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Contact: "Konstantin Vyshetsky" <[email protected]>
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Description: Controls the interval the discard thread will wait between
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issuing discard requests when there are discards to be issued and
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an I/O aware interruption occurs.
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What: /sys/fs/f2fs/<disk>/max_discard_issue_time
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Date: December 2021
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Contact: "Konstantin Vyshetsky" <[email protected]>
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Description: Controls the interval the discard thread will wait when there are
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no discard operations to be issued.
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What: /sys/fs/f2fs/<disk>/discard_granularity
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Date: July 2017
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Contact: "Chao Yu" <[email protected]>
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Description: Controls discard granularity of inner discard thread. Inner thread
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will not issue discards with size that is smaller than granularity.
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The unit size is one block(4KB), now only support configuring
148
in range of [1, 512]. Default value is 16.
149
For small devices, default value is 1.
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What: /sys/fs/f2fs/<disk>/umount_discard_timeout
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Date: January 2019
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Set timeout to issue discard commands during umount.
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Default: 5 secs
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What: /sys/fs/f2fs/<disk>/pending_discard
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Date: November 2021
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Shows the number of pending discard commands in the queue.
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What: /sys/fs/f2fs/<disk>/max_victim_search
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Date: January 2014
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Controls the number of trials to find a victim segment
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when conducting SSR and cleaning operations. The default value
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is 4096 which covers 8GB block address range.
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What: /sys/fs/f2fs/<disk>/migration_granularity
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Date: October 2018
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Contact: "Chao Yu" <[email protected]>
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Description: Controls migration granularity of garbage collection on large
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section, it can let GC move partial segment{s} of one section
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in one GC cycle, so that dispersing heavy overhead GC to
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multiple lightweight one.
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What: /sys/fs/f2fs/<disk>/dir_level
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Date: March 2014
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Controls the directory level for large directory. If a
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directory has a number of files, it can reduce the file lookup
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latency by increasing this dir_level value. Otherwise, it
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needs to decrease this value to reduce the space overhead.
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The default value is 0.
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What: /sys/fs/f2fs/<disk>/ram_thresh
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Date: March 2014
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Controls the memory footprint used by free nids and cached
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nat entries. By default, 1 is set, which indicates
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10 MB / 1 GB RAM.
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What: /sys/fs/f2fs/<disk>/cp_interval
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Date: October 2015
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Controls the checkpoint timing, set to 60 seconds by default.
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What: /sys/fs/f2fs/<disk>/idle_interval
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Date: January 2016
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Controls the idle timing of system, if there is no FS operation
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during given interval.
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Set to 5 seconds by default.
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What: /sys/fs/f2fs/<disk>/discard_idle_interval
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Date: September 2018
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Contact: "Chao Yu" <[email protected]>
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Contact: "Sahitya Tummala" <[email protected]>
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Description: Controls the idle timing of discard thread given
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this time interval.
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Default is 5 secs.
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What: /sys/fs/f2fs/<disk>/gc_idle_interval
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Date: September 2018
215
Contact: "Chao Yu" <[email protected]>
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Contact: "Sahitya Tummala" <[email protected]>
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Description: Controls the idle timing for gc path. Set to 5 seconds by default.
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What: /sys/fs/f2fs/<disk>/iostat_enable
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Date: August 2017
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Contact: "Chao Yu" <[email protected]>
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Description: Controls to enable/disable IO stat.
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What: /sys/fs/f2fs/<disk>/ra_nid_pages
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Date: October 2015
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Contact: "Chao Yu" <[email protected]>
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Description: Controls the count of nid pages to be readaheaded.
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When building free nids, F2FS reads NAT blocks ahead for
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speed up. Default is 0.
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What: /sys/fs/f2fs/<disk>/dirty_nats_ratio
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Date: January 2016
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Contact: "Chao Yu" <[email protected]>
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Description: Controls dirty nat entries ratio threshold, if current
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ratio exceeds configured threshold, checkpoint will
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be triggered for flushing dirty nat entries.
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What: /sys/fs/f2fs/<disk>/lifetime_write_kbytes
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Date: January 2016
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Contact: "Shuoran Liu" <[email protected]>
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Description: Shows total written kbytes issued to disk.
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What: /sys/fs/f2fs/<disk>/features
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Date: July 2017
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: <deprecated: should use /sys/fs/f2fs/<disk>/feature_list/>
247
Shows all enabled features in current device.
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Supported features:
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encryption, blkzoned, extra_attr, projquota, inode_checksum,
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flexible_inline_xattr, quota_ino, inode_crtime, lost_found,
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verity, sb_checksum, casefold, readonly, compression, pin_file.
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What: /sys/fs/f2fs/<disk>/feature_list/
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Date: June 2021
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Expand /sys/fs/f2fs/<disk>/features to meet sysfs rule.
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Supported on-disk features:
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encryption, block_zoned (aka blkzoned), extra_attr,
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project_quota (aka projquota), inode_checksum,
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flexible_inline_xattr, quota_ino, inode_crtime, lost_found,
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verity, sb_checksum, casefold, readonly, compression.
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Note that, pin_file is moved into /sys/fs/f2fs/features/.
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What: /sys/fs/f2fs/features/
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Date: July 2017
266
Contact: "Jaegeuk Kim" <[email protected]>
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Description: Shows all enabled kernel features.
268
Supported features:
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encryption, block_zoned, extra_attr, project_quota,
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inode_checksum, flexible_inline_xattr, quota_ino,
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inode_crtime, lost_found, verity, sb_checksum,
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casefold, readonly, compression, test_dummy_encryption_v2,
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atomic_write, pin_file, encrypted_casefold, linear_lookup.
275
What: /sys/fs/f2fs/<disk>/inject_rate
276
Date: May 2016
277
Contact: "Sheng Yong" <[email protected]>
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Description: Controls the injection rate of arbitrary faults.
280
What: /sys/fs/f2fs/<disk>/inject_type
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Date: May 2016
282
Contact: "Sheng Yong" <[email protected]>
283
Description: Controls the injection type of arbitrary faults.
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What: /sys/fs/f2fs/<disk>/dirty_segments
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Date: October 2017
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Contact: "Jaegeuk Kim" <[email protected]>
288
Description: Shows the number of dirty segments.
290
What: /sys/fs/f2fs/<disk>/reserved_blocks
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Date: June 2017
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Contact: "Chao Yu" <[email protected]>
293
Description: Controls target reserved blocks in system, the threshold
294
is soft, it could exceed current available user space.
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What: /sys/fs/f2fs/<disk>/current_reserved_blocks
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Date: October 2017
298
Contact: "Yunlong Song" <[email protected]>
299
Contact: "Chao Yu" <[email protected]>
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Description: Shows current reserved blocks in system, it may be temporarily
301
smaller than target_reserved_blocks, but will gradually
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increase to target_reserved_blocks when more free blocks are
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freed by user later.
305
What: /sys/fs/f2fs/<disk>/gc_urgent
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Date: August 2017
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Do background GC aggressively when set. Set to 0 by default.
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gc urgent high(1): does GC forcibly in a period of given
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gc_urgent_sleep_time and ignores I/O idling check. uses greedy
311
GC approach and turns SSR mode on.
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gc urgent low(2): lowers the bar of checking I/O idling in
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order to process outstanding discard commands and GC a
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little bit aggressively. always uses cost benefit GC approach,
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and will override age-threshold GC approach if ATGC is enabled
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at the same time.
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gc urgent mid(3): does GC forcibly in a period of given
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gc_urgent_sleep_time and executes a mid level of I/O idling check.
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always uses cost benefit GC approach, and will override
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age-threshold GC approach if ATGC is enabled at the same time.
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What: /sys/fs/f2fs/<disk>/gc_urgent_sleep_time
323
Date: August 2017
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Contact: "Jaegeuk Kim" <[email protected]>
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Description: Controls sleep time of GC urgent mode. Set to 500ms by default.
327
What: /sys/fs/f2fs/<disk>/readdir_ra
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Date: November 2017
329
Contact: "Sheng Yong" <[email protected]>
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Description: Controls readahead inode block in readdir. Enabled by default.
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What: /sys/fs/f2fs/<disk>/gc_pin_file_thresh
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Date: January 2018
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Contact: Jaegeuk Kim <[email protected]>
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Description: This indicates how many GC can be failed for the pinned
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file. If it exceeds this, F2FS doesn't guarantee its pinning
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state. 2048 trials is set by default, and 65535 as maximum.
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What: /sys/fs/f2fs/<disk>/extension_list
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Date: February 2018
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Contact: "Chao Yu" <[email protected]>
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Description: Used to control configure extension list:
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- Query: cat /sys/fs/f2fs/<disk>/extension_list
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- Add: echo '[h/c]extension' > /sys/fs/f2fs/<disk>/extension_list
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- Del: echo '[h/c]!extension' > /sys/fs/f2fs/<disk>/extension_list
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- [h] means add/del hot file extension
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- [c] means add/del cold file extension
349
What: /sys/fs/f2fs/<disk>/unusable
350
Date: April 2019
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Contact: "Daniel Rosenberg" <[email protected]>
352
Description: If checkpoint=disable, it displays the number of blocks that
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are unusable.
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If checkpoint=enable it displays the number of blocks that
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would be unusable if checkpoint=disable were to be set.
357
What: /sys/fs/f2fs/<disk>/encoding
358
Date: July 2019
359
Contact: "Daniel Rosenberg" <[email protected]>
360
Description: Displays name and version of the encoding set for the filesystem.
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If no encoding is set, displays (none)
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What: /sys/fs/f2fs/<disk>/free_segments
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Date: September 2019
365
Contact: "Hridya Valsaraju" <[email protected]>
366
Description: Number of free segments in disk.
368
What: /sys/fs/f2fs/<disk>/cp_foreground_calls
369
Date: September 2019
370
Contact: "Hridya Valsaraju" <[email protected]>
371
Description: Number of checkpoint operations performed on demand. Available when
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CONFIG_F2FS_STAT_FS=y.
374
What: /sys/fs/f2fs/<disk>/cp_background_calls
375
Date: September 2019
376
Contact: "Hridya Valsaraju" <[email protected]>
377
Description: Number of checkpoint operations performed in the background to
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free segments. Available when CONFIG_F2FS_STAT_FS=y.
380
What: /sys/fs/f2fs/<disk>/gc_foreground_calls
381
Date: September 2019
382
Contact: "Hridya Valsaraju" <[email protected]>
383
Description: Number of garbage collection operations performed on demand.
384
Available when CONFIG_F2FS_STAT_FS=y.
386
What: /sys/fs/f2fs/<disk>/gc_background_calls
387
Date: September 2019
388
Contact: "Hridya Valsaraju" <[email protected]>
389
Description: Number of garbage collection operations triggered in background.
390
Available when CONFIG_F2FS_STAT_FS=y.
392
What: /sys/fs/f2fs/<disk>/moved_blocks_foreground
393
Date: September 2019
394
Contact: "Hridya Valsaraju" <[email protected]>
395
Description: Number of blocks moved by garbage collection in foreground.
396
Available when CONFIG_F2FS_STAT_FS=y.
398
What: /sys/fs/f2fs/<disk>/moved_blocks_background
399
Date: September 2019
400
Contact: "Hridya Valsaraju" <[email protected]>
401
Description: Number of blocks moved by garbage collection in background.
402
Available when CONFIG_F2FS_STAT_FS=y.
404
What: /sys/fs/f2fs/<disk>/avg_vblocks
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Date: September 2019
406
Contact: "Hridya Valsaraju" <[email protected]>
407
Description: Average number of valid blocks.
408
Available when CONFIG_F2FS_STAT_FS=y.
410
What: /sys/fs/f2fs/<disk>/mounted_time_sec
411
Date: February 2020
412
Contact: "Jaegeuk Kim" <[email protected]>
413
Description: Show the mounted time in secs of this partition.
415
What: /sys/fs/f2fs/<disk>/data_io_flag
416
Date: April 2020
417
Contact: "Jaegeuk Kim" <[email protected]>
418
Description: Give a way to attach REQ_META|FUA to data writes
419
given temperature-based bits. Now the bits indicate:
421
+-------------------+-------------------+
422
| REQ_META | REQ_FUA |
423
+------+------+-----+------+------+-----+
424
| 5 | 4 | 3 | 2 | 1 | 0 |
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+------+------+-----+------+------+-----+
426
| Cold | Warm | Hot | Cold | Warm | Hot |
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+------+------+-----+------+------+-----+
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What: /sys/fs/f2fs/<disk>/node_io_flag
430
Date: June 2020
431
Contact: "Jaegeuk Kim" <[email protected]>
432
Description: Give a way to attach REQ_META|FUA to node writes
433
given temperature-based bits. Now the bits indicate:
435
+-------------------+-------------------+
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| REQ_META | REQ_FUA |
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+------+------+-----+------+------+-----+
438
| 5 | 4 | 3 | 2 | 1 | 0 |
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+------+------+-----+------+------+-----+
440
| Cold | Warm | Hot | Cold | Warm | Hot |
441
+------+------+-----+------+------+-----+
443
What: /sys/fs/f2fs/<disk>/iostat_period_ms
444
Date: April 2020
445
Contact: "Daeho Jeong" <[email protected]>
446
Description: Give a way to change iostat_period time. 3secs by default.
447
The new iostat trace gives stats gap given the period.
448
What: /sys/fs/f2fs/<disk>/max_io_bytes
449
Date: December 2020
450
Contact: "Jaegeuk Kim" <[email protected]>
451
Description: This gives a control to limit the bio size in f2fs.
452
Default is zero, which will follow underlying block layer limit,
453
whereas, if it has a certain bytes value, f2fs won't submit a
454
bio larger than that size.
456
What: /sys/fs/f2fs/<disk>/stat/sb_status
457
Date: December 2020
458
Contact: "Chao Yu" <[email protected]>
459
Description: Show status of f2fs superblock in real time.
461
====== ===================== =================================
462
value sb status macro description
463
0x1 SBI_IS_DIRTY dirty flag for checkpoint
464
0x2 SBI_IS_CLOSE specify unmounting
465
0x4 SBI_NEED_FSCK need fsck.f2fs to fix
466
0x8 SBI_POR_DOING recovery is doing or not
467
0x10 SBI_NEED_SB_WRITE need to recover superblock
468
0x20 SBI_NEED_CP need to checkpoint
469
0x40 SBI_IS_SHUTDOWN shutdown by ioctl
470
0x80 SBI_IS_RECOVERED recovered orphan/data
471
0x100 SBI_CP_DISABLED CP was disabled last mount
472
0x200 SBI_CP_DISABLED_QUICK CP was disabled quickly
473
0x400 SBI_QUOTA_NEED_FLUSH need to flush quota info in CP
474
0x800 SBI_QUOTA_SKIP_FLUSH skip flushing quota in current CP
475
0x1000 SBI_QUOTA_NEED_REPAIR quota file may be corrupted
476
0x2000 SBI_IS_RESIZEFS resizefs is in process
477
0x4000 SBI_IS_FREEZING freefs is in process
478
====== ===================== =================================
480
What: /sys/fs/f2fs/<disk>/stat/cp_status
481
Date: September 2022
482
Contact: "Chao Yu" <[email protected]>
483
Description: Show status of f2fs checkpoint in real time.
485
=============================== ==============================
486
cp flag value
487
CP_UMOUNT_FLAG 0x00000001
488
CP_ORPHAN_PRESENT_FLAG 0x00000002
489
CP_COMPACT_SUM_FLAG 0x00000004
490
CP_ERROR_FLAG 0x00000008
491
CP_FSCK_FLAG 0x00000010
492
CP_FASTBOOT_FLAG 0x00000020
493
CP_CRC_RECOVERY_FLAG 0x00000040
494
CP_NAT_BITS_FLAG 0x00000080
495
CP_TRIMMED_FLAG 0x00000100
496
CP_NOCRC_RECOVERY_FLAG 0x00000200
497
CP_LARGE_NAT_BITMAP_FLAG 0x00000400
498
CP_QUOTA_NEED_FSCK_FLAG 0x00000800
499
CP_DISABLED_FLAG 0x00001000
500
CP_DISABLED_QUICK_FLAG 0x00002000
501
CP_RESIZEFS_FLAG 0x00004000
502
=============================== ==============================
504
What: /sys/fs/f2fs/<disk>/stat/issued_discard
505
Date: December 2023
506
Contact: "Zhiguo Niu" <[email protected]>
507
Description: Shows the number of issued discard.
509
What: /sys/fs/f2fs/<disk>/stat/queued_discard
510
Date: December 2023
511
Contact: "Zhiguo Niu" <[email protected]>
512
Description: Shows the number of queued discard.
514
What: /sys/fs/f2fs/<disk>/stat/undiscard_blks
515
Date: December 2023
516
Contact: "Zhiguo Niu" <[email protected]>
517
Description: Shows the total number of undiscard blocks.
519
What: /sys/fs/f2fs/<disk>/ckpt_thread_ioprio
520
Date: January 2021
521
Contact: "Daeho Jeong" <[email protected]>
522
Description: Give a way to change checkpoint merge daemon's io priority.
523
Its default value is "be,3", which means "BE" I/O class and
524
I/O priority "3". We can select the class between "rt" and "be",
525
and set the I/O priority within valid range of it. "," delimiter
526
is necessary in between I/O class and priority number.
528
What: /sys/fs/f2fs/<disk>/ovp_segments
529
Date: March 2021
530
Contact: "Jaegeuk Kim" <[email protected]>
531
Description: Shows the number of overprovision segments.
533
What: /sys/fs/f2fs/<disk>/compr_written_block
534
Date: March 2021
535
Contact: "Daeho Jeong" <[email protected]>
536
Description: Show the block count written after compression since mount. Note
537
that when the compressed blocks are deleted, this count doesn't
538
decrease. If you write "0" here, you can initialize
539
compr_written_block and compr_saved_block to "0".
541
What: /sys/fs/f2fs/<disk>/compr_saved_block
542
Date: March 2021
543
Contact: "Daeho Jeong" <[email protected]>
544
Description: Show the saved block count with compression since mount. Note
545
that when the compressed blocks are deleted, this count doesn't
546
decrease. If you write "0" here, you can initialize
547
compr_written_block and compr_saved_block to "0".
549
What: /sys/fs/f2fs/<disk>/compr_new_inode
550
Date: March 2021
551
Contact: "Daeho Jeong" <[email protected]>
552
Description: Show the count of inode newly enabled for compression since mount.
553
Note that when the compression is disabled for the files, this count
554
doesn't decrease. If you write "0" here, you can initialize
555
compr_new_inode to "0".
557
What: /sys/fs/f2fs/<disk>/atgc_candidate_ratio
558
Date: May 2021
559
Contact: "Chao Yu" <[email protected]>
560
Description: When ATGC is on, it controls candidate ratio in order to limit total
561
number of potential victim in all candidates, the value should be in
562
range of [0, 100], by default it was initialized as 20(%).
564
What: /sys/fs/f2fs/<disk>/atgc_candidate_count
565
Date: May 2021
566
Contact: "Chao Yu" <[email protected]>
567
Description: When ATGC is on, it controls candidate count in order to limit total
568
number of potential victim in all candidates, by default it was
569
initialized as 10 (sections).
571
What: /sys/fs/f2fs/<disk>/atgc_age_weight
572
Date: May 2021
573
Contact: "Chao Yu" <[email protected]>
574
Description: When ATGC is on, it controls age weight to balance weight proportion
575
in between aging and valid blocks, the value should be in range of
576
[0, 100], by default it was initialized as 60(%).
578
What: /sys/fs/f2fs/<disk>/atgc_age_threshold
579
Date: May 2021
580
Contact: "Chao Yu" <[email protected]>
581
Description: When ATGC is on, it controls age threshold to bypass GCing young
582
candidates whose age is not beyond the threshold, by default it was
583
initialized as 604800 seconds (equals to 7 days).
585
What: /sys/fs/f2fs/<disk>/atgc_enabled
586
Date: Feb 2024
587
Contact: "Jinbao Liu" <[email protected]>
588
Description: It represents whether ATGC is on or off. The value is 1 which
589
indicates that ATGC is on, and 0 indicates that it is off.
591
What: /sys/fs/f2fs/<disk>/gc_reclaimed_segments
592
Date: July 2021
593
Contact: "Daeho Jeong" <[email protected]>
594
Description: Show how many segments have been reclaimed by GC during a specific
595
GC mode (0: GC normal, 1: GC idle CB, 2: GC idle greedy,
596
3: GC idle AT, 4: GC urgent high, 5: GC urgent low 6: GC urgent mid)
597
You can re-initialize this value to "0".
599
What: /sys/fs/f2fs/<disk>/gc_segment_mode
600
Date: July 2021
601
Contact: "Daeho Jeong" <[email protected]>
602
Description: You can control for which gc mode the "gc_reclaimed_segments" node shows.
603
Refer to the description of the modes in "gc_reclaimed_segments".
605
What: /sys/fs/f2fs/<disk>/seq_file_ra_mul
606
Date: July 2021
607
Contact: "Daeho Jeong" <[email protected]>
608
Description: You can control the multiplier value of bdi device readahead window size
609
between 2 (default) and 256 for POSIX_FADV_SEQUENTIAL advise option.
611
What: /sys/fs/f2fs/<disk>/max_fragment_chunk
612
Date: August 2021
613
Contact: "Daeho Jeong" <[email protected]>
614
Description: With "mode=fragment:block" mount options, we can scatter block allocation.
615
f2fs will allocate 1..<max_fragment_chunk> blocks in a chunk and make a hole
616
in the length of 1..<max_fragment_hole> by turns. This value can be set
617
between 1..512 and the default value is 4.
619
What: /sys/fs/f2fs/<disk>/max_fragment_hole
620
Date: August 2021
621
Contact: "Daeho Jeong" <[email protected]>
622
Description: With "mode=fragment:block" mount options, we can scatter block allocation.
623
f2fs will allocate 1..<max_fragment_chunk> blocks in a chunk and make a hole
624
in the length of 1..<max_fragment_hole> by turns. This value can be set
625
between 1..512 and the default value is 4.
627
What: /sys/fs/f2fs/<disk>/gc_remaining_trials
628
Date: October 2022
629
Contact: "Yangtao Li" <[email protected]>
630
Description: You can set the trial count limit for GC urgent and idle mode with this value.
631
If GC thread gets to the limit, the mode will turn back to GC normal mode.
632
By default, the value is zero, which means there is no limit like before.
634
What: /sys/fs/f2fs/<disk>/max_roll_forward_node_blocks
635
Date: January 2022
636
Contact: "Jaegeuk Kim" <[email protected]>
637
Description: Controls max # of node block writes to be used for roll forward
638
recovery. This can limit the roll forward recovery time.
640
What: /sys/fs/f2fs/<disk>/unusable_blocks_per_sec
641
Date: June 2022
642
Contact: "Jaegeuk Kim" <[email protected]>
643
Description: Shows the number of unusable blocks in a section which was defined by
644
the zone capacity reported by underlying zoned device.
646
What: /sys/fs/f2fs/<disk>/current_atomic_write
647
Date: July 2022
648
Contact: "Daeho Jeong" <[email protected]>
649
Description: Show the total current atomic write block count, which is not committed yet.
650
This is a read-only entry.
652
What: /sys/fs/f2fs/<disk>/peak_atomic_write
653
Date: July 2022
654
Contact: "Daeho Jeong" <[email protected]>
655
Description: Show the peak value of total current atomic write block count after boot.
656
If you write "0" here, you can initialize to "0".
658
What: /sys/fs/f2fs/<disk>/committed_atomic_block
659
Date: July 2022
660
Contact: "Daeho Jeong" <[email protected]>
661
Description: Show the accumulated total committed atomic write block count after boot.
662
If you write "0" here, you can initialize to "0".
664
What: /sys/fs/f2fs/<disk>/revoked_atomic_block
665
Date: July 2022
666
Contact: "Daeho Jeong" <[email protected]>
667
Description: Show the accumulated total revoked atomic write block count after boot.
668
If you write "0" here, you can initialize to "0".
670
What: /sys/fs/f2fs/<disk>/gc_mode
671
Date: October 2022
672
Contact: "Yangtao Li" <[email protected]>
673
Description: Show the current gc_mode as a string.
674
This is a read-only entry.
676
What: /sys/fs/f2fs/<disk>/discard_urgent_util
677
Date: November 2022
678
Contact: "Yangtao Li" <[email protected]>
679
Description: When space utilization exceeds this, do background DISCARD aggressively.
680
Does DISCARD forcibly in a period of given min_discard_issue_time when the number
681
of discards is not 0 and set discard granularity to 1.
682
Default: 80
684
What: /sys/fs/f2fs/<disk>/hot_data_age_threshold
685
Date: November 2022
686
Contact: "Ping Xiong" <[email protected]>
687
Description: When DATA SEPARATION is on, it controls the age threshold to indicate
688
the data blocks as hot. By default it was initialized as 262144 blocks
689
(equals to 1GB).
691
What: /sys/fs/f2fs/<disk>/warm_data_age_threshold
692
Date: November 2022
693
Contact: "Ping Xiong" <[email protected]>
694
Description: When DATA SEPARATION is on, it controls the age threshold to indicate
695
the data blocks as warm. By default it was initialized as 2621440 blocks
696
(equals to 10GB).
698
What: /sys/fs/f2fs/<disk>/fault_rate
699
Date: May 2016
700
Contact: "Sheng Yong" <[email protected]>
701
Contact: "Chao Yu" <[email protected]>
702
Description: Enable fault injection in all supported types with
703
specified injection rate.
705
What: /sys/fs/f2fs/<disk>/fault_type
706
Date: May 2016
707
Contact: "Sheng Yong" <[email protected]>
708
Contact: "Chao Yu" <[email protected]>
709
Description: Support configuring fault injection type, should be
710
enabled with fault_injection option, fault type value
711
is shown below, it supports single or combined type.
713
=========================== ==========
714
Type_Name Type_Value
715
=========================== ==========
716
FAULT_KMALLOC 0x00000001
717
FAULT_KVMALLOC 0x00000002
718
FAULT_PAGE_ALLOC 0x00000004
719
FAULT_PAGE_GET 0x00000008
720
FAULT_ALLOC_BIO 0x00000010 (obsolete)
721
FAULT_ALLOC_NID 0x00000020
722
FAULT_ORPHAN 0x00000040
723
FAULT_BLOCK 0x00000080
724
FAULT_DIR_DEPTH 0x00000100
725
FAULT_EVICT_INODE 0x00000200
726
FAULT_TRUNCATE 0x00000400
727
FAULT_READ_IO 0x00000800
728
FAULT_CHECKPOINT 0x00001000
729
FAULT_DISCARD 0x00002000
730
FAULT_WRITE_IO 0x00004000
731
FAULT_SLAB_ALLOC 0x00008000
732
FAULT_DQUOT_INIT 0x00010000
733
FAULT_LOCK_OP 0x00020000
734
FAULT_BLKADDR_VALIDITY 0x00040000
735
FAULT_BLKADDR_CONSISTENCE 0x00080000
736
FAULT_NO_SEGMENT 0x00100000
737
FAULT_INCONSISTENT_FOOTER 0x00200000
738
FAULT_TIMEOUT 0x00400000 (1000ms)
739
FAULT_VMALLOC 0x00800000
740
=========================== ==========
742
What: /sys/fs/f2fs/<disk>/discard_io_aware_gran
743
Date: January 2023
744
Contact: "Yangtao Li" <[email protected]>
745
Description: Controls background discard granularity of inner discard thread
746
when is not in idle. Inner thread will not issue discards with size that
747
is smaller than granularity. The unit size is one block(4KB), now only
748
support configuring in range of [0, 512].
749
Default: 512
751
What: /sys/fs/f2fs/<disk>/last_age_weight
752
Date: January 2023
753
Contact: "Ping Xiong" <[email protected]>
754
Description: When DATA SEPARATION is on, it controls the weight of last data block age.
756
What: /sys/fs/f2fs/<disk>/compress_watermark
757
Date: February 2023
758
Contact: "Yangtao Li" <[email protected]>
759
Description: When compress cache is on, it controls free memory watermark
760
in order to limit caching compress page. If free memory is lower
761
than watermark, then deny caching compress page. The value should be in
762
range of (0, 100], by default it was initialized as 20(%).
764
What: /sys/fs/f2fs/<disk>/compress_percent
765
Date: February 2023
766
Contact: "Yangtao Li" <[email protected]>
767
Description: When compress cache is on, it controls cached page
768
percent(compress pages / free_ram) in order to limit caching compress page.
769
If cached page percent exceed threshold, then deny caching compress page.
770
The value should be in range of (0, 100], by default it was initialized
771
as 20(%).
773
What: /sys/fs/f2fs/<disk>/discard_io_aware
774
Date: November 2023
775
Contact: "Chao Yu" <[email protected]>
776
Description: It controls to enable/disable IO aware feature for background discard.
777
By default, the value is 1 which indicates IO aware is on.
779
What: /sys/fs/f2fs/<disk>/blkzone_alloc_policy
780
Date: July 2024
781
Contact: "Yuanhong Liao" <[email protected]>
782
Description: The zone UFS we are currently using consists of two parts:
783
conventional zones and sequential zones. It can be used to control which part
784
to prioritize for writes, with a default value of 0.
786
======================== =========================================
787
value description
788
blkzone_alloc_policy = 0 Prioritize writing to sequential zones
789
blkzone_alloc_policy = 1 Only allow writing to sequential zones
790
blkzone_alloc_policy = 2 Prioritize writing to conventional zones
791
======================== =========================================
793
What: /sys/fs/f2fs/<disk>/migration_window_granularity
794
Date: September 2024
795
Contact: "Daeho Jeong" <[email protected]>
796
Description: Controls migration window granularity of garbage collection on large
797
section. it can control the scanning window granularity for GC migration
798
in a unit of segment, while migration_granularity controls the number
799
of segments which can be migrated at the same turn.
801
What: /sys/fs/f2fs/<disk>/reserved_segments
802
Date: September 2024
803
Contact: "Daeho Jeong" <[email protected]>
804
Description: In order to fine tune GC behavior, we can control the number of
805
reserved segments.
807
What: /sys/fs/f2fs/<disk>/gc_no_zoned_gc_percent
808
Date: September 2024
809
Contact: "Daeho Jeong" <[email protected]>
810
Description: If the percentage of free sections over total sections is above this
811
number, F2FS do not garbage collection for zoned devices through the
812
background GC thread. the default number is "60".
814
What: /sys/fs/f2fs/<disk>/gc_boost_zoned_gc_percent
815
Date: September 2024
816
Contact: "Daeho Jeong" <[email protected]>
817
Description: If the percentage of free sections over total sections is under this
818
number, F2FS boosts garbage collection for zoned devices through the
819
background GC thread. the default number is "25".
821
What: /sys/fs/f2fs/<disk>/gc_valid_thresh_ratio
822
Date: September 2024
823
Contact: "Daeho Jeong" <[email protected]>
824
Description: It controls the valid block ratio threshold not to trigger excessive GC
825
for zoned devices. The initial value of it is 95(%). F2FS will stop the
826
background GC thread from initiating GC for sections having valid blocks
827
exceeding the ratio.
829
What: /sys/fs/f2fs/<disk>/max_read_extent_count
830
Date: November 2024
831
Contact: "Chao Yu" <[email protected]>
832
Description: It controls max read extent count for per-inode, the value of threshold
833
is 10240 by default.
835
What: /sys/fs/f2fs/tuning/reclaim_caches_kb
836
Date: February 2025
837
Contact: "Jaegeuk Kim" <[email protected]>
838
Description: It reclaims the given KBs of file-backed pages registered by
839
ioctl(F2FS_IOC_DONATE_RANGE).
840
For example, writing N tries to drop N KBs spaces in LRU.
842
What: /sys/fs/f2fs/<disk>/carve_out
843
Date: March 2025
844
Contact: "Daeho Jeong" <[email protected]>
845
Description: For several zoned storage devices, vendors will provide extra space which
846
was used for device level GC than specs and F2FS can use this space for
847
filesystem level GC. To do that, we can reserve the space using
848
reserved_blocks. However, it is not enough, since this extra space should
849
not be shown to users. So, with this new sysfs node, we can hide the space
850
by subtracting reserved_blocks from total bytes.
852
What: /sys/fs/f2fs/<disk>/encoding_flags
853
Date: April 2025
854
Contact: "Chao Yu" <[email protected]>
855
Description: This is a read-only entry to show the value of sb.s_encoding_flags, the
856
value is hexadecimal.
858
============================ ==========
859
Flag_Name Flag_Value
860
============================ ==========
861
SB_ENC_STRICT_MODE_FL 0x00000001
862
SB_ENC_NO_COMPAT_FALLBACK_FL 0x00000002
863
============================ ==========
865
What: /sys/fs/f2fs/<disk>/reserved_pin_section
866
Date: June 2025
867
Contact: "Chao Yu" <[email protected]>
868
Description: This threshold is used to control triggering garbage collection while
869
fallocating on pinned file, so, it can guarantee there is enough free
870
reserved section before preallocating on pinned file.
871
By default, the value is ovp_sections, especially, for zoned ufs, the
872
value is 1.
874
What: /sys/fs/f2fs/<disk>/gc_boost_gc_multiple
875
Date: June 2025
876
Contact: "Daeho Jeong" <[email protected]>
877
Description: Set a multiplier for the background GC migration window when F2FS GC is
878
boosted. The range should be from 1 to the segment count in a section.
879
Default: 5
881
What: /sys/fs/f2fs/<disk>/gc_boost_gc_greedy
882
Date: June 2025
883
Contact: "Daeho Jeong" <[email protected]>
884
Description: Control GC algorithm for boost GC. 0: cost benefit, 1: greedy
885
Default: 1
887
What: /sys/fs/f2fs/<disk>/effective_lookup_mode
888
Date: August 2025
889
Contact: "Daniel Lee" <[email protected]>
890
Description:
891
This is a read-only entry to show the effective directory lookup mode
892
F2FS is currently using for casefolded directories.
893
This considers both the "lookup_mode" mount option and the on-disk
894
encoding flag, SB_ENC_NO_COMPAT_FALLBACK_FL.
896
Possible values are:
897
- "perf": Hash-only lookup.
898
- "compat": Hash-based lookup with a linear search fallback enabled
899
- "auto:perf": lookup_mode is auto and fallback is disabled on-disk
900
- "auto:compat": lookup_mode is auto and fallback is enabled on-disk
902
What: /sys/fs/f2fs/<disk>/bggc_io_aware
903
Date: August 2025
904
Contact: "Liao Yuanhong" <[email protected]>
905
Description: Used to adjust the BG_GC priority when pending IO, with a default value
906
of 0. Specifically, for ZUFS, the default value is 1.
908
================== ======================================================
909
value description
910
bggc_io_aware = 0 skip background GC if there is any kind of pending IO
911
bggc_io_aware = 1 skip background GC if there is pending read IO
912
bggc_io_aware = 2 don't aware IO for background GC
913
================== ======================================================
915
What: /sys/fs/f2fs/<disk>/allocate_section_hint
916
Date: August 2025
917
Contact: "Liao Yuanhong" <[email protected]>
918
Description: Indicates the hint section between the first device and others in multi-devices
919
setup. It defaults to the end of the first device in sections. For a single storage
920
device, it defaults to the total number of sections. It can be manually set to match
921
scenarios where multi-devices are mapped to the same dm device.
923
What: /sys/fs/f2fs/<disk>/allocate_section_policy
924
Date: August 2025
925
Contact: "Liao Yuanhong" <[email protected]>
926
Description: Controls write priority in multi-devices setups. A value of 0 means normal writing.
927
A value of 1 prioritizes writing to devices before the allocate_section_hint. A value of 2
928
prioritizes writing to devices after the allocate_section_hint. The default is 0.
930
=========================== ==========================================================
931
value description
932
allocate_section_policy = 0 Normal writing
933
allocate_section_policy = 1 Prioritize writing to section before allocate_section_hint
934
allocate_section_policy = 2 Prioritize writing to section after allocate_section_hint
935
=========================== ==========================================================
3. 한국어 전문 번역
영어 원문의 문단 순서와 의미를 유지한 전체 번역입니다. 코드, 함수명, symbol과 URL은 원문 표기를 유지합니다.
F2FS gc max sleep time
1-6| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_max_sleep_time |
| Date | 2013년 7월 |
| Contact | "Namjae Jeon" <[email protected]> |
| Description | GC thread의 최대 sleep time을 제어합니다. 시간 단위는 milliseconds입니다. |
F2FS gc min sleep time
7-12| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_min_sleep_time |
| Date | 2013년 7월 |
| Contact | "Namjae Jeon" <[email protected]> |
| Description | GC thread의 최소 sleep time을 제어합니다. 시간 단위는 milliseconds입니다. |
F2FS gc no gc sleep time
13-18| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_no_gc_sleep_time |
| Date | 2013년 7월 |
| Contact | "Namjae Jeon" <[email protected]> |
| Description | GC할 작업이 없을 때 GC thread가 사용하는 default sleep time을 제어합니다. 시간 단위는 milliseconds입니다. |
F2FS gc idle
19-30| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_idle |
| Date | 2013년 7월 |
| Contact | "Namjae Jeon" <[email protected]> |
| Description | Garbage collection의 victim selection policy를 제어합니다. `0`은 default이며 이 option을 disable합니다. `1`은 Cost Benefit 방식, `2`는 greedy 방식, `3`은 age-threshold 기반 방식을 선택합니다. |
ValuePolicy
0Disabled, default
1Cost Benefit
2Greedy
3Age-threshold
원문의 victim-selection table을 구조화했습니다.
F2FS reclaim segments
31-40| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/reclaim_segments |
| Date | 2013년 10월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Reclaim할 prefree segments 수를 제어합니다. Prefree segment 수가 전체 volume의 segment 수에 대해 이 percentage가 나타내는 수보다 많으면 F2FS가 checkpoint를 수행해 prefree segments를 free segments로 reclaim하려고 합니다. Default는 전체 segments의 5%입니다. |
F2FS main blkaddr
41-45| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/main_blkaddr |
| Date | 2019년 11월 |
| Contact | "Ramon Pantin" <[email protected]> |
| Description | MAIN area의 첫 block address를 표시합니다. |
F2FS ipu policy
46-71| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/ipu_policy |
| Date | 2013년 11월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | F2FS의 in-place-update(IPU) policy를 제어합니다. `0x00 DISABLE`은 IPU를 끄며 LFS mode의 default, `0x01 FORCE`는 항상 IPU, `0x02 SSR`은 SSR mode에서 IPU, `0x04 UTIL`은 filesystem utilization이 threshold를 넘을 때 IPU, `0x08 SSR_UTIL`은 SSR mode이면서 utilization도 threshold를 넘을 때 IPU를 사용합니다. `0x10 FSYNC`은 high-performance flash storage의 fsync path에서 dirty pages가 `min_fsync_blocks`를 넘을 때만 IPU를 trigger하며 default option입니다. `0x20 ASYNC`은 asynchronous write requests에 IPU를 적용하고, `0x40 NOCACHE`는 IPU bio cache를 disable하며, `0x80 HONOR_OPU_WRITE`는 inode에 `FI_OPU_WRITE` flag가 있으면 IPU보다 OPU write를 우선합니다. 자세한 내용은 `segment.h`를 참조합니다. |
ValuePolicyCondition or effect
0x00DISABLEDisable IPU; LFS-mode default
0x01FORCEAlways
0x02SSRSSR mode active
0x04UTILUtilization above threshold
0x08SSR_UTILSSR and utilization threshold
0x10FSYNCFsync dirty pages above min_fsync_blocks
0x20ASYNCAsynchronous writes
0x40NOCACHEDisable IPU bio cache
0x80HONOR_OPU_WRITEPrefer OPU for FI_OPU_WRITE inode
In-place update를 trigger하거나 조정하는 bit values입니다.
F2FS min ipu util
72-77| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/min_ipu_util |
| Date | 2013년 11월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | In-place-update policies의 filesystem utilization 조건을 제어합니다. `F2FS_IPU_UTIL`과 `F2FS_IPU_SSR_UTIL` policies가 이 값을 사용합니다. |
F2FS min fsync blocks
78-83| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/min_fsync_blocks |
| Date | 2014년 9월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | In-place-update policies에 적용하는 dirty page count 조건을 제어합니다. |
F2FS min seq blocks
84-89| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/min_seq_blocks |
| Date | 2018년 8월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | `writepages`에서 batched sequential writes로 처리할 dirty page count 조건을 제어합니다. |
F2FS min hot blocks
90-94| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/min_hot_blocks |
| Date | 2017년 3월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Data를 hot으로 다시 분류하는 dirty page count 조건을 제어합니다. |
F2FS min ssr sections
95-100| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/min_ssr_sections |
| Date | 2017년 10월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | SSR allocation을 trigger할 free section threshold를 제어합니다. 값을 크게 설정할수록 SSR mode가 더 일찍 enable됩니다. |
F2FS max small discards
101-108| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/max_small_discards |
| Date | 2013년 11월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | 2 MB보다 작은 blocks로 구성된 discard commands의 issue rate를 제어합니다. Discard candidates는 checkpoint 중 cache되고 checkpoint 뒤 `issue_discard` thread가 발행합니다. Default로 enabled입니다. |
F2FS max ordered discard
109-114| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/max_ordered_discard |
| Date | 2022년 10월 |
| Contact | "Yangtao Li" <[email protected]> |
| Description | Ordered discard의 최대 크기를 제어합니다. 단위는 block 하나인 4 KB이고 default는 16입니다. |
F2FS max discard request
115-121| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/max_discard_request |
| Date | 2021년 12월 |
| Contact | "Konstantin Vyshetsky" <[email protected]> |
| Description | Discard thread가 한 번에 발행할 discard 수를 제어합니다. 값을 높이면 discard 작업은 빨리 끝나지만 incoming I/O latency가 커질 수 있습니다. |
F2FS min discard issue time
122-128| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/min_discard_issue_time |
| Date | 2021년 12월 |
| Contact | "Konstantin Vyshetsky" <[email protected]> |
| Description | 발행할 discards가 있고 I/O-aware interruption이 발생하지 않았을 때 discard requests 사이에서 thread가 기다릴 interval을 제어합니다. |
F2FS mid discard issue time
129-135| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/mid_discard_issue_time |
| Date | 2021년 12월 |
| Contact | "Konstantin Vyshetsky" <[email protected]> |
| Description | 발행할 discards가 있고 I/O-aware interruption이 발생했을 때 discard requests 사이에서 thread가 기다릴 interval을 제어합니다. |
F2FS max discard issue time
136-141| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/max_discard_issue_time |
| Date | 2021년 12월 |
| Contact | "Konstantin Vyshetsky" <[email protected]> |
| Description | 발행할 discard operation이 없을 때 discard thread가 기다릴 interval을 제어합니다. |
F2FS discard granularity
142-150| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/discard_granularity |
| Date | 2017년 7월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | 내부 discard thread의 discard granularity를 제어합니다. Thread는 granularity보다 작은 discard를 발행하지 않습니다. 단위는 4 KB block 하나이며 범위는 1부터 512, default는 16입니다. Small devices의 default는 1입니다. |
F2FS umount discard timeout
151-156| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/umount_discard_timeout |
| Date | 2019년 1월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Unmount 중 discard commands를 발행할 timeout을 설정합니다. Default는 5 seconds입니다. |
F2FS pending discard
157-161| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/pending_discard |
| Date | 2021년 11월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Queue에 대기 중인 discard commands 수를 표시합니다. |
F2FS max victim search
162-168| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/max_victim_search |
| Date | 2014년 1월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | SSR와 cleaning operations에서 victim segment를 찾기 위한 시도 횟수를 제어합니다. Default 4096은 8 GB block-address range를 포함합니다. |
F2FS migration granularity
169-176| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/migration_granularity |
| Date | 2018년 10월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | Large section에서 garbage collection의 migration granularity를 제어합니다. 한 GC cycle에 section 전체가 아닌 일부 segments만 옮길 수 있게 하여 무거운 GC overhead를 여러 가벼운 cycles로 분산합니다. |
F2FS dir level
177-185| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/dir_level |
| Date | 2014년 3월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Large directory의 directory level을 제어합니다. Files가 많으면 `dir_level`을 높여 lookup latency를 줄일 수 있고, 그렇지 않으면 값을 낮춰 space overhead를 줄여야 합니다. Default는 0입니다. |
F2FS ram thresh
186-192| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/ram_thresh |
| Date | 2014년 3월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Free NIDs와 cached NAT entries가 사용하는 memory footprint를 제어합니다. Default 1은 RAM 1 GB당 10 MB를 뜻합니다. |
F2FS cp interval
193-197| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/cp_interval |
| Date | 2015년 10월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Checkpoint timing을 제어하며 default는 60 seconds입니다. |
F2FS idle interval
198-204| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/idle_interval |
| Date | 2016년 1월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | 주어진 interval 동안 filesystem operation이 없을 때 system을 idle로 판단하는 timing을 제어합니다. Default는 5 seconds입니다. |
F2FS discard idle interval
205-212| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/discard_idle_interval |
| Date | 2018년 9월 |
| Contact | "Chao Yu" <[email protected]>, "Sahitya Tummala" <[email protected]> |
| Description | Discard thread의 idle timing interval을 제어합니다. Default는 5 seconds입니다. |
F2FS gc idle interval
213-218| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_idle_interval |
| Date | 2018년 9월 |
| Contact | "Chao Yu" <[email protected]>, "Sahitya Tummala" <[email protected]> |
| Description | GC path의 idle timing을 제어합니다. Default는 5 seconds입니다. |
F2FS iostat enable
219-223| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/iostat_enable |
| Date | 2017년 8월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | I/O statistics를 enable하거나 disable합니다. |
F2FS ra nid pages
224-230| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/ra_nid_pages |
| Date | 2015년 10월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | Readahead할 NID pages 수를 제어합니다. F2FS는 free NIDs를 만들 때 속도를 높이려고 NAT blocks를 미리 읽습니다. Default는 0입니다. |
F2FS dirty nats ratio
231-237| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/dirty_nats_ratio |
| Date | 2016년 1월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | Dirty NAT entries ratio threshold를 제어합니다. 현재 ratio가 threshold를 넘으면 dirty NAT entries를 flush하기 위해 checkpoint를 trigger합니다. |
F2FS lifetime write kbytes
238-242| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/lifetime_write_kbytes |
| Date | 2016년 1월 |
| Contact | "Shuoran Liu" <[email protected]> |
| Description | Disk에 발행된 전체 write kilobytes를 표시합니다. |
F2FS features
243-252| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/features |
| Date | 2017년 7월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Deprecated된 current-device feature 목록이며 `/sys/fs/f2fs/<disk>/feature_list/`를 사용해야 합니다. 지원 names는 `encryption`, `blkzoned`, `extra_attr`, `projquota`, `inode_checksum`, `flexible_inline_xattr`, `quota_ino`, `inode_crtime`, `lost_found`, `verity`, `sb_checksum`, `casefold`, `readonly`, `compression`, `pin_file`입니다. |
Features
encryption, blkzoned, extra_attr, projquota
inode_checksum, flexible_inline_xattr, quota_ino
inode_crtime, lost_found, verity, sb_checksum
casefold, readonly, compression, pin_file
Legacy feature file에 표시되는 on-disk names입니다.
F2FS feature list
253-263| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/feature_list/ |
| Date | 2021년 6월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Sysfs 규칙을 충족하도록 `/sys/fs/f2fs/<disk>/features`를 확장한 on-disk feature directory입니다. 지원 names는 `encryption`, `block_zoned`(`blkzoned`), `extra_attr`, `project_quota`(`projquota`), `inode_checksum`, `flexible_inline_xattr`, `quota_ino`, `inode_crtime`, `lost_found`, `verity`, `sb_checksum`, `casefold`, `readonly`, `compression`입니다. `pin_file`은 `/sys/fs/f2fs/features/`로 이동했습니다. |
NameAlias or note
block_zonedblkzoned
project_quotaprojquota
pin_fileMoved to global kernel-feature directory
Other namesencryption through compression
Sysfs-compliant on-disk feature names와 aliases입니다.
F2FS features
264-274| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/features/ |
| Date | 2017년 7월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | 활성화된 kernel features를 표시합니다. 지원 names는 `encryption`, `block_zoned`, `extra_attr`, `project_quota`, `inode_checksum`, `flexible_inline_xattr`, `quota_ino`, `inode_crtime`, `lost_found`, `verity`, `sb_checksum`, `casefold`, `readonly`, `compression`, `test_dummy_encryption_v2`, `atomic_write`, `pin_file`, `encrypted_casefold`, `linear_lookup`입니다. |
Feature groupNames
On-disk relatedencryption through compression
Testingtest_dummy_encryption_v2
Writeatomic_write, pin_file
Lookupencrypted_casefold, linear_lookup
Kernel-level support names입니다.
F2FS inject rate
275-279| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/inject_rate |
| Date | 2016년 5월 |
| Contact | "Sheng Yong" <[email protected]> |
| Description | 임의 fault의 injection rate를 제어합니다. |
F2FS inject type
280-284| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/inject_type |
| Date | 2016년 5월 |
| Contact | "Sheng Yong" <[email protected]> |
| Description | 임의 fault의 injection type을 제어합니다. |
F2FS dirty segments
285-289| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/dirty_segments |
| Date | 2017년 10월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Dirty segments 수를 표시합니다. |
F2FS reserved blocks
290-295| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/reserved_blocks |
| Date | 2017년 6월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | System의 target reserved blocks를 제어합니다. Threshold는 soft limit이므로 현재 userspace가 사용할 수 있는 공간보다 클 수 있습니다. |
F2FS current reserved blocks
296-304| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/current_reserved_blocks |
| Date | 2017년 10월 |
| Contact | "Yunlong Song" <[email protected]>, "Chao Yu" <[email protected]> |
| Description | System의 current reserved blocks를 표시합니다. 일시적으로 `target_reserved_blocks`보다 작을 수 있지만 user가 나중에 더 많은 free blocks를 만들면 점차 target까지 증가합니다. |
F2FS gc urgent
305-321| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_urgent |
| Date | 2017년 8월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Background GC의 공격성을 제어하며 default는 0입니다. High mode `1`은 `gc_urgent_sleep_time` 주기마다 GC를 강제로 수행하고 I/O idle 검사를 무시하며 greedy GC와 SSR을 사용합니다. Low mode `2`는 outstanding discard commands와 조금 더 공격적인 GC를 위해 I/O idle 판단 기준을 낮추고 항상 Cost Benefit GC를 사용하며 ATGC가 동시에 enabled여도 age-threshold 방식을 override합니다. Mid mode `3`은 같은 주기로 GC를 강제하되 중간 수준의 I/O idle 검사를 하고 Cost Benefit GC를 사용하며 ATGC를 override합니다. |
ValueModeI/O idleAlgorithm
0NormalNormalConfigured policy
1Urgent highIgnoredGreedy + SSR
2Urgent lowRelaxedCost Benefit
3Urgent midMid-level checkCost Benefit
I/O-idle handling과 GC algorithm을 비교합니다.
F2FS gc urgent sleep time
322-326| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_urgent_sleep_time |
| Date | 2017년 8월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | GC urgent mode의 sleep time을 제어합니다. Default는 500 ms입니다. |
F2FS readdir ra
327-331| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/readdir_ra |
| Date | 2017년 11월 |
| Contact | "Sheng Yong" <[email protected]> |
| Description | `readdir`에서 inode-block readahead를 제어하며 default로 enabled입니다. |
F2FS gc pin file thresh
332-338| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_pin_file_thresh |
| Date | 2018년 1월 |
| Contact | Jaegeuk Kim <[email protected]> |
| Description | Pinned file에서 허용할 GC failure 횟수를 나타냅니다. 이를 넘으면 F2FS가 pinning state를 보장하지 않습니다. Default는 2048 trials이고 maximum은 65535입니다. |
F2FS extension list
339-348| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/extension_list |
| Date | 2018년 2월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | File extension list를 조회·추가·삭제합니다. 조회는 `cat /sys/fs/f2fs/<disk>/extension_list`, 추가는 `echo '[h/c]extension' > ...`, 삭제는 `echo '[h/c]!extension' > ...` 형식입니다. `[h]`는 hot-file extension, `[c]`는 cold-file extension을 뜻합니다. |
OperationSyntax
Querycat .../extension_list
Addecho '[h/c]extension' > .../extension_list
Deleteecho '[h/c]!extension' > .../extension_list
Hot·cold extension query와 mutation syntax입니다.
cat /sys/fs/f2fs/<disk>/extension_list
echo '[h/c]extension' > /sys/fs/f2fs/<disk>/extension_list
echo '[h/c]!extension' > /sys/fs/f2fs/<disk>/extension_listF2FS unusable
349-356| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/unusable |
| Date | 2019년 4월 |
| Contact | "Daniel Rosenberg" <[email protected]> |
| Description | `checkpoint=disable`이면 실제 unusable blocks 수를 표시합니다. Checkpoint가 enabled이면 이를 disable했을 때 unusable해질 blocks 수를 표시합니다. |
F2FS encoding
357-362| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/encoding |
| Date | 2019년 7월 |
| Contact | "Daniel Rosenberg" <[email protected]> |
| Description | Filesystem에 설정된 encoding의 name과 version을 표시합니다. Encoding이 없으면 `(none)`을 표시합니다. |
F2FS free segments
363-367| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/free_segments |
| Date | 2019년 9월 |
| Contact | "Hridya Valsaraju" <[email protected]> |
| Description | Disk의 free segments 수를 표시합니다. |
F2FS cp foreground calls
368-373| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/cp_foreground_calls |
| Date | 2019년 9월 |
| Contact | "Hridya Valsaraju" <[email protected]> |
| Description | 요청에 따라 수행한 checkpoint operations 수입니다. `CONFIG_F2FS_STAT_FS=y`일 때 사용할 수 있습니다. |
F2FS cp background calls
374-379| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/cp_background_calls |
| Date | 2019년 9월 |
| Contact | "Hridya Valsaraju" <[email protected]> |
| Description | Free segments를 만들기 위해 background에서 수행한 checkpoint operations 수입니다. `CONFIG_F2FS_STAT_FS=y`일 때 사용할 수 있습니다. |
F2FS gc foreground calls
380-385| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_foreground_calls |
| Date | 2019년 9월 |
| Contact | "Hridya Valsaraju" <[email protected]> |
| Description | 요청에 따라 수행한 garbage collection operations 수입니다. `CONFIG_F2FS_STAT_FS=y`일 때 사용할 수 있습니다. |
F2FS gc background calls
386-391| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_background_calls |
| Date | 2019년 9월 |
| Contact | "Hridya Valsaraju" <[email protected]> |
| Description | Background에서 trigger된 garbage collection operations 수입니다. `CONFIG_F2FS_STAT_FS=y`일 때 사용할 수 있습니다. |
F2FS moved blocks foreground
392-397| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/moved_blocks_foreground |
| Date | 2019년 9월 |
| Contact | "Hridya Valsaraju" <[email protected]> |
| Description | Foreground garbage collection이 이동한 blocks 수입니다. `CONFIG_F2FS_STAT_FS=y`일 때 사용할 수 있습니다. |
F2FS moved blocks background
398-403| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/moved_blocks_background |
| Date | 2019년 9월 |
| Contact | "Hridya Valsaraju" <[email protected]> |
| Description | Background garbage collection이 이동한 blocks 수입니다. `CONFIG_F2FS_STAT_FS=y`일 때 사용할 수 있습니다. |
F2FS avg vblocks
404-409| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/avg_vblocks |
| Date | 2019년 9월 |
| Contact | "Hridya Valsaraju" <[email protected]> |
| Description | Average valid-block count를 표시합니다. `CONFIG_F2FS_STAT_FS=y`일 때 사용할 수 있습니다. |
F2FS mounted time sec
410-414| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/mounted_time_sec |
| Date | 2020년 2월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | 이 partition이 mount된 시간을 seconds 단위로 표시합니다. |
F2FS data io flag
415-428| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/data_io_flag |
| Date | 2020년 4월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Temperature-based bits로 data writes에 `REQ_META` 또는 `REQ_FUA`를 붙입니다. Bits 5·4·3은 각각 Cold·Warm·Hot data의 `REQ_META`, bits 2·1·0은 각각 Cold·Warm·Hot data의 `REQ_FUA`를 제어합니다. |
FlagColdWarmHot
REQ_METABit 5Bit 4Bit 3
REQ_FUABit 2Bit 1Bit 0
ASCII bit diagram을 구조화했습니다.
F2FS node io flag
429-442| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/node_io_flag |
| Date | 2020년 6월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Temperature-based bits로 node writes에 `REQ_META` 또는 `REQ_FUA`를 붙입니다. Bits 5·4·3은 각각 Cold·Warm·Hot node의 `REQ_META`, bits 2·1·0은 각각 Cold·Warm·Hot node의 `REQ_FUA`를 제어합니다. |
FlagColdWarmHot
REQ_METABit 5Bit 4Bit 3
REQ_FUABit 2Bit 1Bit 0
Node-write ASCII bit diagram을 구조화했습니다.
F2FS iostat period ms
443-447| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/iostat_period_ms |
| Date | 2020년 4월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | I/O statistics period를 변경합니다. Default는 3 seconds이며 새 iostat trace는 이 period에 따른 statistics gap을 제공합니다. |
F2FS max io bytes
448-455| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/max_io_bytes |
| Date | 2020년 12월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | F2FS가 제출하는 bio size를 제한합니다. Default 0은 underlying block-layer limit을 따르고, byte value를 설정하면 그보다 큰 bio를 제출하지 않습니다. |
F2FS sb status
456-479| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/stat/sb_status |
| Date | 2020년 12월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | F2FS superblock status를 실시간 bitmask로 표시합니다. `0x1 SBI_IS_DIRTY`는 checkpoint dirty, `0x2 SBI_IS_CLOSE`는 unmounting, `0x4 SBI_NEED_FSCK`는 `fsck.f2fs` repair 필요, `0x8 SBI_POR_DOING`은 recovery 진행, `0x10 SBI_NEED_SB_WRITE`는 superblock recovery 필요, `0x20 SBI_NEED_CP`는 checkpoint 필요, `0x40 SBI_IS_SHUTDOWN`은 ioctl shutdown, `0x80 SBI_IS_RECOVERED`는 orphan/data recovery를 뜻합니다. `0x100 SBI_CP_DISABLED`와 `0x200 SBI_CP_DISABLED_QUICK`은 이전 mount의 CP disable 상태, `0x400 SBI_QUOTA_NEED_FLUSH`와 `0x800 SBI_QUOTA_SKIP_FLUSH`는 quota flush 정책, `0x1000 SBI_QUOTA_NEED_REPAIR`는 quota corruption 가능성, `0x2000 SBI_IS_RESIZEFS`는 resizefs 진행, `0x4000 SBI_IS_FREEZING`은 freefs 진행을 뜻합니다. |
ValueMacroMeaning
0x1SBI_IS_DIRTYCheckpoint dirty
0x2SBI_IS_CLOSEUnmounting
0x4SBI_NEED_FSCKNeeds fsck.f2fs
0x8SBI_POR_DOINGRecovery in progress
0x10SBI_NEED_SB_WRITERecover superblock
0x20SBI_NEED_CPNeeds checkpoint
0x40SBI_IS_SHUTDOWNioctl shutdown
0x80SBI_IS_RECOVEREDOrphan/data recovered
0x100SBI_CP_DISABLEDCP disabled last mount
0x200SBI_CP_DISABLED_QUICKCP disabled quickly
0x400SBI_QUOTA_NEED_FLUSHFlush quota in CP
0x800SBI_QUOTA_SKIP_FLUSHSkip quota flush
0x1000SBI_QUOTA_NEED_REPAIRQuota may be corrupt
0x2000SBI_IS_RESIZEFSResize in progress
0x4000SBI_IS_FREEZINGFreeze in progress
실시간 `sb_status` bitmask입니다.
F2FS cp status
480-503| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/stat/cp_status |
| Date | 2022년 9월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | F2FS checkpoint status를 실시간 bitmask로 표시합니다. Flags는 `CP_UMOUNT_FLAG 0x00000001`, `CP_ORPHAN_PRESENT_FLAG 0x00000002`, `CP_COMPACT_SUM_FLAG 0x00000004`, `CP_ERROR_FLAG 0x00000008`, `CP_FSCK_FLAG 0x00000010`, `CP_FASTBOOT_FLAG 0x00000020`, `CP_CRC_RECOVERY_FLAG 0x00000040`, `CP_NAT_BITS_FLAG 0x00000080`, `CP_TRIMMED_FLAG 0x00000100`, `CP_NOCRC_RECOVERY_FLAG 0x00000200`, `CP_LARGE_NAT_BITMAP_FLAG 0x00000400`, `CP_QUOTA_NEED_FSCK_FLAG 0x00000800`, `CP_DISABLED_FLAG 0x00001000`, `CP_DISABLED_QUICK_FLAG 0x00002000`, `CP_RESIZEFS_FLAG 0x00004000`입니다. |
FlagValue
CP_UMOUNT_FLAG0x00000001
CP_ORPHAN_PRESENT_FLAG0x00000002
CP_COMPACT_SUM_FLAG0x00000004
CP_ERROR_FLAG0x00000008
CP_FSCK_FLAG0x00000010
CP_FASTBOOT_FLAG0x00000020
CP_CRC_RECOVERY_FLAG0x00000040
CP_NAT_BITS_FLAG0x00000080
CP_TRIMMED_FLAG0x00000100
CP_NOCRC_RECOVERY_FLAG0x00000200
CP_LARGE_NAT_BITMAP_FLAG0x00000400
CP_QUOTA_NEED_FSCK_FLAG0x00000800
CP_DISABLED_FLAG0x00001000
CP_DISABLED_QUICK_FLAG0x00002000
CP_RESIZEFS_FLAG0x00004000
실시간 `cp_status` flags와 values입니다.
F2FS issued discard
504-508| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/stat/issued_discard |
| Date | 2023년 12월 |
| Contact | "Zhiguo Niu" <[email protected]> |
| Description | 발행한 discard 수를 표시합니다. |
F2FS queued discard
509-513| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/stat/queued_discard |
| Date | 2023년 12월 |
| Contact | "Zhiguo Niu" <[email protected]> |
| Description | Queue에 넣은 discard 수를 표시합니다. |
F2FS undiscard blks
514-518| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/stat/undiscard_blks |
| Date | 2023년 12월 |
| Contact | "Zhiguo Niu" <[email protected]> |
| Description | 아직 discard하지 않은 blocks의 전체 수를 표시합니다. |
F2FS ckpt thread ioprio
519-527| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/ckpt_thread_ioprio |
| Date | 2021년 1월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | Checkpoint merge daemon의 I/O priority를 변경합니다. Default `be,3`은 BE I/O class와 priority 3을 뜻합니다. Class는 `rt` 또는 `be`, priority는 해당 class의 valid range에서 선택하며 class와 number 사이에 comma delimiter가 반드시 필요합니다. |
ExampleClassPriority
be,3Best effort3
Class와 priority를 comma로 결합합니다.
F2FS ovp segments
528-532| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/ovp_segments |
| Date | 2021년 3월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Overprovision segments 수를 표시합니다. |
F2FS compr written block
533-540| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/compr_written_block |
| Date | 2021년 3월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | Mount 뒤 compression을 거쳐 write한 block count를 표시합니다. Compressed blocks가 삭제되어도 감소하지 않습니다. `0`을 쓰면 `compr_written_block`과 `compr_saved_block`을 모두 0으로 초기화합니다. |
F2FS compr saved block
541-548| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/compr_saved_block |
| Date | 2021년 3월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | Mount 뒤 compression으로 절약한 block count를 표시합니다. Compressed blocks가 삭제되어도 감소하지 않습니다. `0`을 쓰면 `compr_written_block`과 `compr_saved_block`을 모두 0으로 초기화합니다. |
F2FS compr new inode
549-556| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/compr_new_inode |
| Date | 2021년 3월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | Mount 뒤 새로 compression이 enabled된 inode 수를 표시합니다. Files에서 compression을 disable해도 감소하지 않습니다. `0`을 쓰면 `compr_new_inode`를 0으로 초기화합니다. |
AttributeMeaningReset
compr_written_blockCompressed blocks writtenWrite 0; also resets saved
compr_saved_blockBlocks saved by compressionWrite 0; also resets written
compr_new_inodeNew compression-enabled inodesWrite 0
Mount 이후 누적되며 삭제·disable로 감소하지 않는 counters입니다.
F2FS atgc candidate ratio
557-563| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/atgc_candidate_ratio |
| Date | 2021년 5월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | ATGC가 enabled일 때 전체 candidates 중 potential victims의 총수를 제한하는 candidate ratio입니다. 범위는 0부터 100이고 default는 20%입니다. |
F2FS atgc candidate count
564-570| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/atgc_candidate_count |
| Date | 2021년 5월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | ATGC가 enabled일 때 전체 candidates 중 potential victims의 총수를 제한하는 candidate count입니다. Default는 10 sections입니다. |
F2FS atgc age weight
571-577| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/atgc_age_weight |
| Date | 2021년 5월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | ATGC가 enabled일 때 aging과 valid blocks 사이의 weight 비율을 조정하는 age weight입니다. 범위는 0부터 100이고 default는 60%입니다. |
F2FS atgc age threshold
578-584| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/atgc_age_threshold |
| Date | 2021년 5월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | ATGC가 enabled일 때 threshold를 넘지 않은 young candidates의 GC를 건너뛰는 age threshold입니다. Default는 604800 seconds, 즉 7 days입니다. |
F2FS atgc enabled
585-590| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/atgc_enabled |
| Date | 2024년 2월 |
| Contact | "Jinbao Liu" <[email protected]> |
| Description | ATGC enable 상태를 나타냅니다. `1`은 on, `0`은 off입니다. |
AttributeRange or default
atgc_candidate_ratio0..100, default 20%
atgc_candidate_countDefault 10 sections
atgc_age_weight0..100, default 60%
atgc_age_thresholdDefault 604800 s / 7 days
atgc_enabled1 on, 0 off
Candidate limiting과 age weighting parameters입니다.
F2FS gc reclaimed segments
591-598| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_reclaimed_segments |
| Date | 2021년 7월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | 선택한 GC mode에서 reclaim한 segments 수를 표시합니다. Modes는 `0` normal, `1` idle Cost Benefit, `2` idle greedy, `3` idle age-threshold, `4` urgent high, `5` urgent low, `6` urgent mid입니다. `0`으로 다시 초기화할 수 있습니다. |
ValueMode
0GC normal
1GC idle Cost Benefit
2GC idle greedy
3GC idle age-threshold
4GC urgent high
5GC urgent low
6GC urgent mid
Counter가 선택할 수 있는 GC mode IDs입니다.
F2FS gc segment mode
599-604| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_segment_mode |
| Date | 2021년 7월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | `gc_reclaimed_segments`가 어느 GC mode의 값을 표시할지 선택합니다. Mode 정의는 `gc_reclaimed_segments` 설명을 따릅니다. |
F2FS seq file ra mul
605-610| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/seq_file_ra_mul |
| Date | 2021년 7월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | `POSIX_FADV_SEQUENTIAL` advise에 사용할 BDI device readahead window-size multiplier를 2부터 256 사이로 제어합니다. Default는 2입니다. |
F2FS max fragment chunk
611-618| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/max_fragment_chunk |
| Date | 2021년 8월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | `mode=fragment:block` mount option에서 block allocation을 흩뜨리기 위한 chunk 크기입니다. F2FS는 `1..<max_fragment_chunk>` blocks를 할당한 뒤 `1..<max_fragment_hole>` 길이의 hole을 번갈아 만듭니다. 범위는 1부터 512이고 default는 4입니다. |
F2FS max fragment hole
619-626| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/max_fragment_hole |
| Date | 2021년 8월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | `mode=fragment:block` mount option에서 block allocation 사이에 만들 hole의 최대 길이입니다. F2FS는 chunk allocation과 `1..<max_fragment_hole>` hole을 번갈아 만듭니다. 범위는 1부터 512이고 default는 4입니다. |
Allocate 1..<max_fragment_chunk> blocks→Create 1..<max_fragment_hole> block hole→Repeat chunk and hole
`mode=fragment:block`에서 chunk와 hole을 번갈아 만듭니다.
F2FS gc remaining trials
627-633| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_remaining_trials |
| Date | 2022년 10월 |
| Contact | "Yangtao Li" <[email protected]> |
| Description | GC urgent·idle mode의 trial-count limit를 설정합니다. GC thread가 limit에 도달하면 normal mode로 돌아갑니다. Default 0은 제한이 없음을 뜻합니다. |
F2FS max roll forward node blocks
634-639| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/max_roll_forward_node_blocks |
| Date | 2022년 1월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Roll-forward recovery에 사용할 node-block writes의 maximum을 제어하여 recovery time을 제한합니다. |
F2FS unusable blocks per sec
640-645| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/unusable_blocks_per_sec |
| Date | 2022년 6월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | Underlying zoned device가 보고한 zone capacity로 정의되는 section당 unusable blocks 수를 표시합니다. |
F2FS current atomic write
646-651| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/current_atomic_write |
| Date | 2022년 7월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | 아직 commit되지 않은 current atomic-write blocks의 전체 수를 표시하는 read-only entry입니다. |
F2FS peak atomic write
652-657| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/peak_atomic_write |
| Date | 2022년 7월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | Boot 뒤 current atomic-write block count가 기록한 peak를 표시합니다. `0`을 쓰면 0으로 초기화합니다. |
F2FS committed atomic block
658-663| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/committed_atomic_block |
| Date | 2022년 7월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | Boot 뒤 commit된 atomic-write blocks의 누적 전체 수를 표시합니다. `0`을 쓰면 0으로 초기화합니다. |
F2FS revoked atomic block
664-669| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/revoked_atomic_block |
| Date | 2022년 7월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | Boot 뒤 revoke된 atomic-write blocks의 누적 전체 수를 표시합니다. `0`을 쓰면 0으로 초기화합니다. |
AttributeScopeReset
current_atomic_writeCurrent uncommittedRead-only
peak_atomic_writePeak after bootWrite 0
committed_atomic_blockAccumulated committed after bootWrite 0
revoked_atomic_blockAccumulated revoked after bootWrite 0
Current, peak, committed와 revoked block counts입니다.
F2FS gc mode
670-675| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_mode |
| Date | 2022년 10월 |
| Contact | "Yangtao Li" <[email protected]> |
| Description | Current `gc_mode`를 string으로 표시하는 read-only entry입니다. |
F2FS discard urgent util
676-683| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/discard_urgent_util |
| Date | 2022년 11월 |
| Contact | "Yangtao Li" <[email protected]> |
| Description | Space utilization이 이 threshold를 넘으면 background DISCARD를 공격적으로 수행합니다. Pending discards가 0이 아니면 `min_discard_issue_time` 주기로 DISCARD를 강제하고 granularity를 1로 설정합니다. Default는 80입니다. |
F2FS hot data age threshold
684-690| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/hot_data_age_threshold |
| Date | 2022년 11월 |
| Contact | "Ping Xiong" <[email protected]> |
| Description | DATA SEPARATION이 enabled일 때 data blocks를 hot으로 표시할 age threshold입니다. Default는 262144 blocks, 즉 1 GB입니다. |
F2FS warm data age threshold
691-697| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/warm_data_age_threshold |
| Date | 2022년 11월 |
| Contact | "Ping Xiong" <[email protected]> |
| Description | DATA SEPARATION이 enabled일 때 data blocks를 warm으로 표시할 age threshold입니다. Default는 2621440 blocks, 즉 10 GB입니다. |
F2FS fault rate
698-704| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/fault_rate |
| Date | 2016년 5월 |
| Contact | "Sheng Yong" <[email protected]>, "Chao Yu" <[email protected]> |
| Description | 지정한 injection rate로 지원하는 모든 fault types의 fault injection을 enable합니다. |
F2FS fault type
705-741| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/fault_type |
| Date | 2016년 5월 |
| Contact | "Sheng Yong" <[email protected]>, "Chao Yu" <[email protected]> |
| Description | `fault_injection` option과 함께 사용할 fault-injection type bitmask를 설정합니다. 단일 type 또는 여러 types의 OR 조합을 지원합니다. Type values는 `FAULT_KMALLOC 0x00000001`, `FAULT_KVMALLOC 0x00000002`, `FAULT_PAGE_ALLOC 0x00000004`, `FAULT_PAGE_GET 0x00000008`, obsolete `FAULT_ALLOC_BIO 0x00000010`, `FAULT_ALLOC_NID 0x00000020`, `FAULT_ORPHAN 0x00000040`, `FAULT_BLOCK 0x00000080`, `FAULT_DIR_DEPTH 0x00000100`, `FAULT_EVICT_INODE 0x00000200`, `FAULT_TRUNCATE 0x00000400`, `FAULT_READ_IO 0x00000800`, `FAULT_CHECKPOINT 0x00001000`, `FAULT_DISCARD 0x00002000`, `FAULT_WRITE_IO 0x00004000`, `FAULT_SLAB_ALLOC 0x00008000`, `FAULT_DQUOT_INIT 0x00010000`, `FAULT_LOCK_OP 0x00020000`, `FAULT_BLKADDR_VALIDITY 0x00040000`, `FAULT_BLKADDR_CONSISTENCE 0x00080000`, `FAULT_NO_SEGMENT 0x00100000`, `FAULT_INCONSISTENT_FOOTER 0x00200000`, `FAULT_TIMEOUT 0x00400000`(1000 ms), `FAULT_VMALLOC 0x00800000`입니다. |
TypeValue
FAULT_KMALLOC0x00000001
FAULT_KVMALLOC0x00000002
FAULT_PAGE_ALLOC0x00000004
FAULT_PAGE_GET0x00000008
FAULT_ALLOC_BIO (obsolete)0x00000010
FAULT_ALLOC_NID0x00000020
FAULT_ORPHAN0x00000040
FAULT_BLOCK0x00000080
FAULT_DIR_DEPTH0x00000100
FAULT_EVICT_INODE0x00000200
FAULT_TRUNCATE0x00000400
FAULT_READ_IO0x00000800
FAULT_CHECKPOINT0x00001000
FAULT_DISCARD0x00002000
FAULT_WRITE_IO0x00004000
FAULT_SLAB_ALLOC0x00008000
FAULT_DQUOT_INIT0x00010000
FAULT_LOCK_OP0x00020000
FAULT_BLKADDR_VALIDITY0x00040000
FAULT_BLKADDR_CONSISTENCE0x00080000
FAULT_NO_SEGMENT0x00100000
FAULT_INCONSISTENT_FOOTER0x00200000
FAULT_TIMEOUT0x00400000 / 1000 ms
FAULT_VMALLOC0x00800000
단일 또는 OR-combined fault injection bitmask입니다.
F2FS discard io aware gran
742-750| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/discard_io_aware_gran |
| Date | 2023년 1월 |
| Contact | "Yangtao Li" <[email protected]> |
| Description | Idle 상태가 아닐 때 내부 discard thread의 background discard granularity를 제어합니다. Thread는 이보다 작은 discard를 발행하지 않습니다. 단위는 4 KB block이고 범위는 0부터 512, default는 512입니다. |
F2FS last age weight
751-755| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/last_age_weight |
| Date | 2023년 1월 |
| Contact | "Ping Xiong" <[email protected]> |
| Description | DATA SEPARATION이 enabled일 때 마지막 data block age의 weight를 제어합니다. |
F2FS compress watermark
756-763| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/compress_watermark |
| Date | 2023년 2월 |
| Contact | "Yangtao Li" <[email protected]> |
| Description | Compression cache가 enabled일 때 compressed-page caching을 제한하는 free-memory watermark입니다. Free memory가 watermark보다 낮으면 compressed page를 cache하지 않습니다. 범위는 0 초과 100 이하이고 default는 20%입니다. |
F2FS compress percent
764-772| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/compress_percent |
| Date | 2023년 2월 |
| Contact | "Yangtao Li" <[email protected]> |
| Description | Compression cache가 enabled일 때 `compressed pages / free RAM` 비율을 제한합니다. Cached-page percentage가 threshold를 넘으면 compressed page caching을 거부합니다. 범위는 0 초과 100 이하이고 default는 20%입니다. |
AttributeDeny caching whenRangeDefault
compress_watermarkFree memory below watermark(0, 100]20%
compress_percentCompressed pages / free RAM above threshold(0, 100]20%
Memory watermark와 cache percentage를 함께 적용합니다.
F2FS discard io aware
773-778| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/discard_io_aware |
| Date | 2023년 11월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | Background discard의 I/O-aware feature를 enable하거나 disable합니다. Default 1은 I/O-aware가 on임을 뜻합니다. |
F2FS blkzone alloc policy
779-792| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/blkzone_alloc_policy |
| Date | 2024년 7월 |
| Contact | "Yuanhong Liao" <[email protected]> |
| Description | Conventional zones와 sequential zones로 구성된 zoned UFS에서 write allocation 우선순위를 정합니다. Default `0`은 sequential zones 우선, `1`은 sequential zones에만 write 허용, `2`는 conventional zones 우선입니다. |
ValuePolicy
0Prioritize sequential zones
1Sequential zones only
2Prioritize conventional zones
Sequential·conventional zone write priority입니다.
F2FS migration window granularity
793-800| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/migration_window_granularity |
| Date | 2024년 9월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | Large section GC의 migration scanning-window granularity를 segments 단위로 제어합니다. `migration_granularity`가 한 번에 옮길 segment 수를 제어하는 것과 달리 이 값은 scan window 크기를 정합니다. |
F2FS reserved segments
801-806| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/reserved_segments |
| Date | 2024년 9월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | GC behavior를 세밀하게 조정하기 위한 reserved segments 수를 제어합니다. |
F2FS gc no zoned gc percent
807-813| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_no_zoned_gc_percent |
| Date | 2024년 9월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | 전체 sections 중 free sections 비율이 이 값보다 높으면 background GC thread가 zoned devices에 GC를 수행하지 않습니다. Default는 60입니다. |
F2FS gc boost zoned gc percent
814-820| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_boost_zoned_gc_percent |
| Date | 2024년 9월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | 전체 sections 중 free sections 비율이 이 값보다 낮으면 background GC thread가 zoned-device GC를 boost합니다. Default는 25입니다. |
F2FS gc valid thresh ratio
821-828| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_valid_thresh_ratio |
| Date | 2024년 9월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | Zoned devices에서 excessive GC를 막기 위한 valid-block ratio threshold입니다. Initial value는 95%이며 section의 valid-block ratio가 이를 넘으면 background GC thread가 그 section에 GC를 시작하지 않습니다. |
AttributeThresholdEffect
gc_no_zoned_gc_percentDefault 60Above: do not run zoned GC
gc_boost_zoned_gc_percentDefault 25Below: boost zoned GC
gc_valid_thresh_ratioDefault 95%Above valid ratio: skip section GC
Free-section과 valid-block ratios에 따른 background behavior입니다.
F2FS max read extent count
829-834| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/max_read_extent_count |
| Date | 2024년 11월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | Inode당 maximum read-extent count를 제어합니다. Default threshold는 10240입니다. |
F2FS reclaim caches kb
835-841| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/tuning/reclaim_caches_kb |
| Date | 2025년 2월 |
| Contact | "Jaegeuk Kim" <[email protected]> |
| Description | `ioctl(F2FS_IOC_DONATE_RANGE)`로 등록한 file-backed pages를 지정한 KB만큼 reclaim합니다. `N`을 쓰면 LRU에서 N KB 공간을 drop하려고 합니다. |
F2FS carve out
842-851| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/carve_out |
| Date | 2025년 3월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | 일부 zoned storage vendors가 specification보다 추가로 제공하는 device-level GC 공간을 F2FS filesystem-level GC에 사용하면서 userspace에는 숨깁니다. `reserved_blocks`로 공간을 reserve한 뒤 이 node가 total bytes에서 `reserved_blocks`를 빼 표시합니다. |
F2FS encoding flags
852-864| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/encoding_flags |
| Date | 2025년 4월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | `sb.s_encoding_flags` 값을 hexadecimal로 표시하는 read-only entry입니다. `SB_ENC_STRICT_MODE_FL`은 `0x00000001`, `SB_ENC_NO_COMPAT_FALLBACK_FL`은 `0x00000002`입니다. |
FlagValue
SB_ENC_STRICT_MODE_FL0x00000001
SB_ENC_NO_COMPAT_FALLBACK_FL0x00000002
Hexadecimal `sb.s_encoding_flags` values입니다.
F2FS reserved pin section
865-873| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/reserved_pin_section |
| Date | 2025년 6월 |
| Contact | "Chao Yu" <[email protected]> |
| Description | Pinned file에 `fallocate`할 때 GC trigger를 제어하는 threshold로, preallocation 전에 충분한 free reserved sections를 보장합니다. Default는 `ovp_sections`이며 zoned UFS에서는 특히 1입니다. |
F2FS gc boost gc multiple
874-880| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_boost_gc_multiple |
| Date | 2025년 6월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | F2FS GC가 boosted일 때 background-GC migration window에 적용할 multiplier입니다. 범위는 1부터 section 안의 segment count까지이고 default는 5입니다. |
F2FS gc boost gc greedy
881-886| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/gc_boost_gc_greedy |
| Date | 2025년 6월 |
| Contact | "Daeho Jeong" <[email protected]> |
| Description | Boost GC algorithm을 제어합니다. `0`은 Cost Benefit, `1`은 greedy이며 default는 1입니다. |
AttributeValuesDefault
gc_boost_gc_multiple1..segments per section5
gc_boost_gc_greedy0 Cost Benefit, 1 greedy1
Migration window multiplier와 algorithm입니다.
F2FS effective lookup mode
887-901| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/effective_lookup_mode |
| Date | 2025년 8월 |
| Contact | "Daniel Lee" <[email protected]> |
| Description | Casefolded directories에 F2FS가 현재 사용하는 effective lookup mode를 표시하는 read-only entry입니다. `lookup_mode` mount option과 on-disk `SB_ENC_NO_COMPAT_FALLBACK_FL`을 함께 고려합니다. `perf`는 hash-only, `compat`는 hash lookup 뒤 linear fallback, `auto:perf`는 auto이면서 on-disk fallback disabled, `auto:compat`는 auto이면서 fallback enabled입니다. |
ValueBehavior
perfHash-only lookup
compatHash lookup with linear fallback
auto:perfAuto with on-disk fallback disabled
auto:compatAuto with on-disk fallback enabled
Mount option과 on-disk fallback flag의 effective 결과입니다.
F2FS bggc io aware
902-914| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/bggc_io_aware |
| Date | 2025년 8월 |
| Contact | "Liao Yuanhong" <[email protected]> |
| Description | Pending I/O가 있을 때 BG_GC priority를 조정합니다. General default는 0이고 ZUFS default는 1입니다. `0`은 어떤 pending I/O든 있으면 background GC를 skip하고, `1`은 pending read I/O가 있을 때 skip하며, `2`는 background GC가 I/O를 고려하지 않습니다. |
ValueBehavior
0Skip for any pending I/O
1Skip for pending read I/O
2Ignore I/O for background GC
Pending I/O 종류에 따른 BG_GC skip policy입니다.
F2FS allocate section hint
915-922| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/allocate_section_hint |
| Date | 2025년 8월 |
| Contact | "Liao Yuanhong" <[email protected]> |
| Description | Multi-device setup에서 첫 device와 나머지를 가르는 hint section을 나타냅니다. Default는 section 단위로 첫 device의 끝이며 single device에서는 전체 section 수입니다. 여러 devices가 같은 device-mapper device에 mapping된 경우에 맞게 수동 설정할 수 있습니다. |
F2FS allocate section policy
923-935| 항목 | 한국어 전문 번역 |
|---|---|
| What | /sys/fs/f2fs/<disk>/allocate_section_policy |
| Date | 2025년 8월 |
| Contact | "Liao Yuanhong" <[email protected]> |
| Description | Multi-device setup의 write priority를 제어합니다. Default `0`은 normal write, `1`은 `allocate_section_hint` 앞의 devices를 우선하고, `2`는 hint 뒤의 devices를 우선합니다. |
ValuePolicy
0Normal writing
1Prioritize sections before hint
2Prioritize sections after hint
`allocate_section_hint`를 기준으로 write priority를 정합니다.
Garbage collection and discard
sysfs-fs-f2fs:1-242GC sleep·victim·migration policies와 IPU, discard granularity·batch·timing, checkpoint·NAT memory tuning을 다룹니다.