Re: Ext4 documentation

Andreas Dilger
2008-12-22T23:45:12Z

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.