1 What: /sys/fs/ext4/<disk>/mb_stats
3 Contact: "Theodore Ts'o" <tytso@mit.edu>
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
10 What: /sys/fs/ext4/<disk>/mb_group_prealloc
12 Contact: "Theodore Ts'o" <tytso@mit.edu>
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
18 What: /sys/fs/ext4/<disk>/mb_max_to_scan
20 Contact: "Theodore Ts'o" <tytso@mit.edu>
22 The maximum number of extents the multiblock allocator
23 will search to find the best extent
25 What: /sys/fs/ext4/<disk>/mb_min_to_scan
27 Contact: "Theodore Ts'o" <tytso@mit.edu>
29 The minimum number of extents the multiblock allocator
30 will search to find the best extent
32 What: /sys/fs/ext4/<disk>/mb_order2_req
34 Contact: "Theodore Ts'o" <tytso@mit.edu>
36 Tuning parameter which controls the minimum size for
37 requests (as a power of 2) where the buddy cache is
40 What: /sys/fs/ext4/<disk>/mb_stream_req
42 Contact: "Theodore Ts'o" <tytso@mit.edu>
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
51 What: /sys/fs/ext4/<disk>/inode_readahead
53 Contact: "Theodore Ts'o" <tytso@mit.edu>
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
59 What: /sys/fs/ext4/<disk>/delayed_allocation_blocks
61 Contact: "Theodore Ts'o" <tytso@mit.edu>
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.
67 What: /sys/fs/ext4/<disk>/lifetime_write_kbytes
69 Contact: "Theodore Ts'o" <tytso@mit.edu>
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
75 What: /sys/fs/ext4/<disk>/session_write_kbytes
77 Contact: "Theodore Ts'o" <tytso@mit.edu>
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.