path: root/Documentation
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authorDavid Sterba <>2017-01-12 15:00:47 +0100
committerDavid Sterba <>2017-01-25 09:47:43 +0100
commit52f21fc76965b4c7b39bc5e3d0f6e044f1ddb693 (patch)
tree4db0726a943385dfce4e8560f1635097d35499d4 /Documentation
parentb757cf4ba76b433769722622734c54b7c7e175a8 (diff)
btrfs-progs: defrag: force using v2 defrag ioctl and make default 32M threshold actually work
A user reported on IRC that the new 32M default for target extent size does not work. This happens because if there are no commandline options, the v1 ioctl is used that does not do any fine grained defrag. As the v2 ioctl has been introduced 6 years ago (2010, kernel 2.6.33) we won't keep backward compatibility anymore. Signed-off-by: David Sterba <>
Diffstat (limited to 'Documentation')
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/btrfs-filesystem.asciidoc b/Documentation/btrfs-filesystem.asciidoc
index 9782af9b..0f7ea495 100644
--- a/Documentation/btrfs-filesystem.asciidoc
+++ b/Documentation/btrfs-filesystem.asciidoc
@@ -80,7 +80,7 @@ show sizes in TiB, or TB with --si
If conflicting options are passed, the last one takes precedence.
*defragment* [options] <file>|<dir> [<file>|<dir>...]::
-Defragment file data on a mounted filesystem.
+Defragment file data on a mounted filesystem. Requires kernel 2.6.33 and newer.
If '-r' is passed, files in dir will be defragmented recursively.
The start position and the number of bytes to defragment can be specified by