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Commit 22359f57 authored by Diego Calleja's avatar Diego Calleja Committed by Theodore Ts'o
Browse files

ext4: Update Documentation/filesystems/ext4.txt 



Since Ext4 is supposed to be stable in 2.6.28-rc, ext4's documentation
file should be updated.

[ More updates also added by Theodore Ts'o. ]

Signed-off-by: default avatarDiego Calleja <diegocg@gmail.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 01436ef2

Documentation/filesystems/ext4.txt

+15 −17
Original line number Original line Diff line number Diff line
@@ -2,19 +2,24 @@ 
Ext4 Filesystem

Ext4 Filesystem

===============

===============





This is a development version of the ext4 filesystem, an advanced level

Ext4 is an an advanced level of the ext3 filesystem which incorporates

of the ext3 filesystem which incorporates scalability and reliability

scalability and reliability enhancements for supporting large filesystems

enhancements for supporting large filesystems (64 bit) in keeping with

(64 bit) in keeping with increasing disk capacities and state-of-the-art

increasing disk capacities and state-of-the-art feature requirements.

feature requirements.





Mailing list:	linux-ext4@vger.kernel.org

Mailing list:	linux-ext4@vger.kernel.org

Web site:	http://ext4.wiki.kernel.org









1. Quick usage instructions:

1. Quick usage instructions:

===========================

===========================





Note: More extensive information for getting started with ext4 can be

      found at the ext4 wiki site at the URL:

      http://ext4.wiki.kernel.org/index.php/Ext4_Howto



  - Compile and install the latest version of e2fsprogs (as of this

  - Compile and install the latest version of e2fsprogs (as of this

    writing version 1.41) from:

    writing version 1.41.3) from:





    http://sourceforge.net/project/showfiles.php?group_id=2406

    http://sourceforge.net/project/showfiles.php?group_id=2406
@@ -36,11 +41,9 @@ Mailing list: linux-ext4@vger.kernel.org 




    	# mke2fs -t ext4 /dev/hda1

    	# mke2fs -t ext4 /dev/hda1





    Or configure an existing ext3 filesystem to support extents and set

    Or to configure an existing ext3 filesystem to support extents: 

    the test_fs flag to indicate that it's ok for an in-development

    filesystem to touch this filesystem:





	# tune2fs -O extents -E test_fs /dev/hda1

	# tune2fs -O extents /dev/hda1





    If the filesystem was created with 128 byte inodes, it can be

    If the filesystem was created with 128 byte inodes, it can be

    converted to use 256 byte for greater efficiency via:

    converted to use 256 byte for greater efficiency via:
@@ -104,8 +107,8 @@ exist yet so I'm not sure they're in the near-term roadmap. 
The big performance win will come with mballoc, delalloc and flex_bg

The big performance win will come with mballoc, delalloc and flex_bg

grouping of bitmaps and inode tables.  Some test results available here:

grouping of bitmaps and inode tables.  Some test results available here:





 - http://www.bullopensource.org/ext4/20080530/ffsb-write-2.6.26-rc2.html

 - http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-write-2.6.27-rc1.html

 - http://www.bullopensource.org/ext4/20080530/ffsb-readwrite-2.6.26-rc2.html

 - http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-readwrite-2.6.27-rc1.html





3. Options

3. Options

==========

==========
@@ -214,9 +217,6 @@ noreservation 
bsddf		(*)	Make 'df' act like BSD.

bsddf		(*)	Make 'df' act like BSD.

minixdf			Make 'df' act like Minix.

minixdf			Make 'df' act like Minix.





check=none		Don't do extra checking of bitmaps on mount.

nocheck



debug			Extra debugging information is sent to syslog.

debug			Extra debugging information is sent to syslog.





errors=remount-ro(*)	Remount the filesystem read-only on an error.

errors=remount-ro(*)	Remount the filesystem read-only on an error.
@@ -253,8 +253,6 @@ nobh (a) cache disk block mapping information 
			"nobh" option tries to avoid associating buffer

			"nobh" option tries to avoid associating buffer

			heads (supported only for "writeback" mode).

			heads (supported only for "writeback" mode).





mballoc		(*)	Use the multiple block allocator for block allocation

nomballoc		disabled multiple block allocator for block allocation.

stripe=n		Number of filesystem blocks that mballoc will try

stripe=n		Number of filesystem blocks that mballoc will try

			to use for allocation size and alignment. For RAID5/6

			to use for allocation size and alignment. For RAID5/6

			systems this should be the number of data

			systems this should be the number of data