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Commit | Line | Data |
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3197ebdb TT |
1 | What: /sys/fs/ext4/<disk>/mb_stats |
2 | Date: March 2008 | |
3 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
4 | Description: | |
5 | Controls whether the multiblock allocator should | |
6 | collect statistics, which are shown during the unmount. | |
7 | 1 means to collect statistics, 0 means not to collect | |
8 | statistics | |
9 | ||
10 | What: /sys/fs/ext4/<disk>/mb_group_prealloc | |
11 | Date: March 2008 | |
12 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
13 | Description: | |
14 | The multiblock allocator will round up allocation | |
15 | requests to a multiple of this tuning parameter if the | |
16 | stripe size is not set in the ext4 superblock | |
17 | ||
18 | What: /sys/fs/ext4/<disk>/mb_max_to_scan | |
19 | Date: March 2008 | |
20 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
21 | Description: | |
22 | The maximum number of extents the multiblock allocator | |
23 | will search to find the best extent | |
24 | ||
25 | What: /sys/fs/ext4/<disk>/mb_min_to_scan | |
26 | Date: March 2008 | |
27 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
28 | Description: | |
29 | The minimum number of extents the multiblock allocator | |
30 | will search to find the best extent | |
31 | ||
32 | What: /sys/fs/ext4/<disk>/mb_order2_req | |
33 | Date: March 2008 | |
34 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
35 | Description: | |
36 | Tuning parameter which controls the minimum size for | |
37 | requests (as a power of 2) where the buddy cache is | |
38 | used | |
39 | ||
40 | What: /sys/fs/ext4/<disk>/mb_stream_req | |
41 | Date: March 2008 | |
42 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
43 | Description: | |
44 | Files which have fewer blocks than this tunable | |
45 | parameter will have their blocks allocated out of a | |
46 | block group specific preallocation pool, so that small | |
47 | files are packed closely together. Each large file | |
48 | will have its blocks allocated out of its own unique | |
49 | preallocation pool. | |
50 | ||
6f9524e9 | 51 | What: /sys/fs/ext4/<disk>/inode_readahead_blks |
3197ebdb TT |
52 | Date: March 2008 |
53 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
54 | Description: | |
55 | Tuning parameter which controls the maximum number of | |
56 | inode table blocks that ext4's inode table readahead | |
57 | algorithm will pre-read into the buffer cache | |
58 | ||
59 | What: /sys/fs/ext4/<disk>/delayed_allocation_blocks | |
60 | Date: March 2008 | |
61 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
62 | Description: | |
63 | This file is read-only and shows the number of blocks | |
64 | that are dirty in the page cache, but which do not | |
65 | have their location in the filesystem allocated yet. | |
66 | ||
67 | What: /sys/fs/ext4/<disk>/lifetime_write_kbytes | |
68 | Date: March 2008 | |
69 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
70 | Description: | |
71 | This file is read-only and shows the number of kilobytes | |
72 | of data that have been written to this filesystem since it was | |
73 | created. | |
74 | ||
75 | What: /sys/fs/ext4/<disk>/session_write_kbytes | |
76 | Date: March 2008 | |
77 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
78 | Description: | |
79 | This file is read-only and shows the number of | |
80 | kilobytes of data that have been written to this | |
81 | filesystem since it was mounted. | |
11013911 AD |
82 | |
83 | What: /sys/fs/ext4/<disk>/inode_goal | |
84 | Date: June 2008 | |
85 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
86 | Description: | |
87 | Tuning parameter which (if non-zero) controls the goal | |
6f9524e9 LC |
88 | inode used by the inode allocator in preference to |
89 | all other allocation heuristics. This is intended for | |
11013911 AD |
90 | debugging use only, and should be 0 on production |
91 | systems. | |
6f9524e9 LC |
92 | |
93 | What: /sys/fs/ext4/<disk>/max_writeback_mb_bump | |
94 | Date: September 2009 | |
95 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
96 | Description: | |
97 | The maximum number of megabytes the writeback code will | |
98 | try to write out before move on to another inode. | |
67a5da56 ZL |
99 | |
100 | What: /sys/fs/ext4/<disk>/extent_max_zeroout_kb | |
101 | Date: August 2012 | |
102 | Contact: "Theodore Ts'o" <tytso@mit.edu> | |
103 | Description: | |
104 | The maximum number of kilobytes which will be zeroed | |
105 | out in preference to creating a new uninitialized | |
106 | extent when manipulating an inode's extent tree. Note | |
107 | that using a larger value will increase the | |
108 | variability of time necessary to complete a random | |
109 | write operation (since a 4k random write might turn | |
110 | into a much larger write due to the zeroout | |
111 | operation). |