e4defrag man page on ElementaryOS

Man page or keyword search:  
man Server   4994 pages
apropos Keyword Search (all sections)
Output format
ElementaryOS logo
[printable version]

E4DEFRAG(8)							   E4DEFRAG(8)

NAME
       e4defrag - online defragmenter for ext4 filesystem

SYNOPSIS
       e4defrag [ -c ] [ -v ] target ...

DESCRIPTION
       e4defrag	 reduces fragmentation of extent based file. The file targeted
       by e4defrag is created on ext4 filesystem made with "-O extent"	option
       (see  mke2fs(8)).   The	targeted  file gets more contiguous blocks and
       improves the file access speed.

       target is a regular file, a directory, or a device that is  mounted  as
       ext4 filesystem.	 If target is a directory, e4defrag reduces fragmenta‐
       tion of all files in it. If target is a device, e4defrag gets the mount
       point of it and reduces fragmentation of all files in this mount point.

OPTIONS
       -c     Get  a  current  fragmentation  count and an ideal fragmentation
	      count, and calculate fragmentation score based on them. By  see‐
	      ing  this	 score,	 we  can  determine  whether we should execute
	      e4defrag to target.  When used with -v option, the current frag‐
	      mentation	 count	and  the ideal fragmentation count are printed
	      for each file.

	      Also this option outputs the average data size in one extent. If
	      you  see it, you'll find the file has ideal extents or not. Note
	      that the maximum extent size is 131072KB in ext4 filesystem  (if
	      block size is 4KB).

	      If this option is specified, target is never defragmented.

       -v     Print  error  messages  and  the	fragmentation count before and
	      after defrag for each file.

NOTES
       e4defrag does not support swap file, files in lost+found directory, and
       files  allocated in indirect blocks. When target is a device or a mount
       point, e4defrag doesn't	defragment  files  in  mount  point  of	 other
       device.

       Non-privileged  users  can  execute e4defrag to their own file, but the
       score is not printed if -c option is specified. Therefore, it is desir‐
       able to be executed by root user.

AUTHOR
       Written	by  Akira Fujita <a-fujita@rs.jp.nec.com> and Takashi Sato <t-
       sato@yk.jp.nec.com>.

SEE ALSO
       mke2fs(8), mount(8).

e4defrag version 2.0		   May 2009			   E4DEFRAG(8)
[top]

List of man pages available for ElementaryOS

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
...................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net