112 lines
3.7 KiB
Text
112 lines
3.7 KiB
Text
|
What: /sys/fs/ext4/<disk>/mb_stats
|
||
|
|
Date: March 2008
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
Controls whether the multiblock allocator should
|
||
|
|
collect statistics, which are shown during the unmount.
|
||
|
|
1 means to collect statistics, 0 means not to collect
|
||
|
|
statistics
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/mb_group_prealloc
|
||
|
|
Date: March 2008
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
The multiblock allocator will round up allocation
|
||
|
|
requests to a multiple of this tuning parameter if the
|
||
|
|
stripe size is not set in the ext4 superblock
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/mb_max_to_scan
|
||
|
|
Date: March 2008
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
The maximum number of extents the multiblock allocator
|
||
|
|
will search to find the best extent
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/mb_min_to_scan
|
||
|
|
Date: March 2008
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
The minimum number of extents the multiblock allocator
|
||
|
|
will search to find the best extent
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/mb_order2_req
|
||
|
|
Date: March 2008
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
Tuning parameter which controls the minimum size for
|
||
|
|
requests (as a power of 2) where the buddy cache is
|
||
|
|
used
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/mb_stream_req
|
||
|
|
Date: March 2008
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
Files which have fewer blocks than this tunable
|
||
|
|
parameter will have their blocks allocated out of a
|
||
|
|
block group specific preallocation pool, so that small
|
||
|
|
files are packed closely together. Each large file
|
||
|
|
will have its blocks allocated out of its own unique
|
||
|
|
preallocation pool.
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/inode_readahead_blks
|
||
|
|
Date: March 2008
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
Tuning parameter which controls the maximum number of
|
||
|
|
inode table blocks that ext4's inode table readahead
|
||
|
|
algorithm will pre-read into the buffer cache
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/delayed_allocation_blocks
|
||
|
|
Date: March 2008
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
This file is read-only and shows the number of blocks
|
||
|
|
that are dirty in the page cache, but which do not
|
||
|
|
have their location in the filesystem allocated yet.
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/lifetime_write_kbytes
|
||
|
|
Date: March 2008
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
This file is read-only and shows the number of kilobytes
|
||
|
|
of data that have been written to this filesystem since it was
|
||
|
|
created.
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/session_write_kbytes
|
||
|
|
Date: March 2008
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
This file is read-only and shows the number of
|
||
|
|
kilobytes of data that have been written to this
|
||
|
|
filesystem since it was mounted.
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/inode_goal
|
||
|
|
Date: June 2008
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
Tuning parameter which (if non-zero) controls the goal
|
||
|
|
inode used by the inode allocator in preference to
|
||
|
|
all other allocation heuristics. This is intended for
|
||
|
|
debugging use only, and should be 0 on production
|
||
|
|
systems.
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/max_writeback_mb_bump
|
||
|
|
Date: September 2009
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
The maximum number of megabytes the writeback code will
|
||
|
|
try to write out before move on to another inode.
|
||
|
|
|
||
|
|
What: /sys/fs/ext4/<disk>/extent_max_zeroout_kb
|
||
|
|
Date: August 2012
|
||
|
|
Contact: "Theodore Ts'o" <tytso@mit.edu>
|
||
|
|
Description:
|
||
|
|
The maximum number of kilobytes which will be zeroed
|
||
|
|
out in preference to creating a new uninitialized
|
||
|
|
extent when manipulating an inode's extent tree. Note
|
||
|
|
that using a larger value will increase the
|
||
|
|
variability of time necessary to complete a random
|
||
|
|
write operation (since a 4k random write might turn
|
||
|
|
into a much larger write due to the zeroout
|
||
|
|
operation).
|