From: Andreas Dilger <adilger@sun.com>
Subject: Re: Ext4 documentation
Date: Mon, 22 Dec 2008 16:44:56 -0700
Message-ID: <20081222234456.GW5000@webber.adilger.int>
References: <20081222235841.7aaaef93@diego-desktop>
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Cc: linux-ext4@vger.kernel.org
To: Diego Calleja <diegocg@gmail.com>
In-reply-to: <20081222235841.7aaaef93@diego-desktop>
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Sender: linux-ext4-owner@vger.kernel.org

On Dec 22, 2008  23:58 +0100, Diego Calleja wrote:
> Due to the astounding lack of good end-user documentation about Ext4, I've
> taken the freedom of writing an article about it for the kernelnewbies
> 2.6.28 changelog: http://kernelnewbies.org/Ext4
> 
> If you find any error or you have some suggestion, just tell me and I'll
> fix it.

Looks pretty good, thanks for writing this up.  Minor notes:
- While > 16TB is supported by ext4 disk formats, the mke2fs/e2fsck code
  to support this is not in any released e2fsprogs yet
- I don't think the journal async commit blocks are enabled by default, so
  the "20% speedup" is not available yet.  There is some work that
  needs to be done to make this feature 100% safe in case of corruption.
- I'm not sure if enabling flex_bg on an existing ext3 filesystem is useful
- you don't mention anything about the required e2fsprogs version.  I
  _think_ (someone should confirm) that e2fsprogs-1.41.3 is the minimum
  version that anyone should use.

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.