1 .TH E4DEFRAG 8 "May 2009" "e4defrag version 2.0"
3 e4defrag \- online defragmenter for ext4 filesystem
16 reduces fragmentation of extent based file. The file targeted by
18 is created on ext4 filesystem made with "-O extent" option (see
20 The targeted file gets more contiguous blocks and improves the file access
24 is a regular file, a directory, or a device that is mounted as ext4 filesystem.
29 reduces fragmentation of all files in it. If
33 gets the mount point of it and reduces fragmentation of all files in this mount
38 Get the fragmentation count and calculate fragmentation score based on it
39 before and after defrag. By seeing this score, we can determine whether we
46 option, the fragmentation count before and after defrag is printed for each
49 If this option is specified,
51 is never defragmented.
54 Print error messages and the fragmentation count before and after defrag for
58 does not support swap file, files in lost+found directory, and files allocated
59 in indirect blocks. When
61 is a device or a mount point,
63 doesn't defragment files in mount point of other device.
65 Non-privileged users can execute
67 to their own file, but the score is not printed if
69 option is specified. Therefore, it is desirable to be executed by root user.
71 Written by Akira Fujita <a-fujita@rs.jp.nec.com> and Takashi Sato
72 <t-sato@yk.jp.nec.com>.