2008-10-16 23:09:53

by Diego Calleja

[permalink] [raw]
Subject: [PATCH] Update Documentation/filesystems/ext4.txt

Since Ext4 is supposed to be stable in 2.6.28-rc, Documentation should be
updated...it needs more updates, of course, I don't really know what
parts should really be updated

PD: the wiki needs some update aswell.


Signed-off-by: Diego Calleja <[email protected]>

Index: 2.6/Documentation/filesystems/ext4.txt
===================================================================
--- 2.6.orig/Documentation/filesystems/ext4.txt 2008-10-17 01:01:50.000000000 +0200
+++ 2.6/Documentation/filesystems/ext4.txt 2008-10-17 01:04:38.000000000 +0200
@@ -2,10 +2,10 @@
Ext4 Filesystem
===============

-This is a development version of the ext4 filesystem, an advanced level
-of the ext3 filesystem which incorporates scalability and reliability
-enhancements for supporting large filesystems (64 bit) in keeping with
-increasing disk capacities and state-of-the-art feature requirements.
+Ext4 is an an advanced level of the ext3 filesystem which incorporates
+scalability and reliability enhancements for supporting large filesystems
+(64 bit) in keeping with increasing disk capacities and state-of-the-art
+feature requirements.

Mailing list: [email protected]

@@ -40,7 +40,7 @@
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
converted to use 256 byte for greater efficiency via:
@@ -68,7 +68,7 @@

2.1 Currently available

-* ability to use filesystems > 16TB (e2fsprogs support not available yet)
+* ability to use filesystems > 16TB
* extent format reduces metadata overhead (RAM, IO for access, transactions)
* extent format more robust in face of on-disk corruption due to magics,
* internal redunancy in tree
@@ -101,12 +101,6 @@
metadata checksumming have been discussed and planned for a bit but no patches
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
-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/ext4/20080530/ffsb-readwrite-2.6.26-rc2.html


2008-10-17 11:11:59

by Theodore Ts'o

[permalink] [raw]
Subject: Re: [PATCH] Update Documentation/filesystems/ext4.txt

On Fri, Oct 17, 2008 at 01:10:08AM +0200, dcg wrote:
> Since Ext4 is supposed to be stable in 2.6.28-rc, Documentation should be
> updated...it needs more updates, of course, I don't really know what
> parts should really be updated

Thanks, here's the revised version of the patch which I have in the
ext4 patch queue.

> PD: the wiki needs some update aswell.

I'll update the wiki after 2.6.28-rc1 and the merge window closes.

- Ted

ext4: Update Documentation/filesystems/ext4.txt

From: dcg <[email protected]>

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: Diego Calleja <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>


Index: 2.6/Documentation/filesystems/ext4.txt
===================================================================
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index eb154ef..7fd9b9b 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -2,10 +2,10 @@
Ext4 Filesystem
===============

-This is a development version of the ext4 filesystem, an advanced level
-of the ext3 filesystem which incorporates scalability and reliability
-enhancements for supporting large filesystems (64 bit) in keeping with
-increasing disk capacities and state-of-the-art feature requirements.
+Ext4 is an an advanced level of the ext3 filesystem which incorporates
+scalability and reliability enhancements for supporting large filesystems
+(64 bit) in keeping with increasing disk capacities and state-of-the-art
+feature requirements.

Mailing list: [email protected]

@@ -14,7 +14,7 @@ Mailing list: [email protected]
===========================

- 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

@@ -36,11 +36,9 @@ Mailing list: [email protected]

# mke2fs -t ext4 /dev/hda1

- Or configure an existing ext3 filesystem to support extents and set
- the test_fs flag to indicate that it's ok for an in-development
- filesystem to touch this filesystem:
+ Or to configure an existing ext3 filesystem to support extents:

- # 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
converted to use 256 byte for greater efficiency via:
@@ -104,8 +102,8 @@ 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
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/ext4/20080530/ffsb-readwrite-2.6.26-rc2.html
+ - http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-write-2.6.27-rc1.html
+ - http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-readwrite-2.6.27-rc1.html

3. Options
==========
@@ -253,8 +251,6 @@ nobh (a) cache disk block mapping information
"nobh" option tries to avoid associating buffer
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
to use for allocation size and alignment. For RAID5/6
systems this should be the number of data