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From: "Jörn Engel" <joern@logfs.org>
To: Phillip Lougher <phillip@lougher.demon.co.uk>
Cc: Arnd Bergmann <arnd@arndb.de>,
	jaredeh@gmail.com, Linux-kernel@vger.kernel.org,
	linux-embedded@vger.kernel.org,
	linux-mtd <linux-mtd@lists.infradead.org>,
	tim.bird@am.sony.com, cotte@de.ibm.com, nickpiggin@yahoo.com.au
Subject: Re: [PATCH 04/10] AXFS: axfs_inode.c
Date: Fri, 22 Aug 2008 19:19:59 +0200	[thread overview]
Message-ID: <20080822171959.GA30977@logfs.org> (raw)
In-Reply-To: <48AEF2A3.7020905@lougher.demon.co.uk>

On Fri, 22 August 2008 18:08:51 +0100, Phillip Lougher wrote:
> 
> Squashfs stores significantly more metadata than cramfs.  Remember 
> cramfs has no support for filesystems > ~ 16Mbytes, no inode timestamps, 
> truncates uid/gids, no hard-links, no nlink counts, no hashed 
> directories,  no unique inode numbers.  If Squashfs didn't compress the 
> metadata it would be significantly larger than cramfs.

Elsewhere in this maze of threads Arnd claimed to have tested the
benefits of metadata compression - and it making little impact.

My guess is that it would make a large impact if metadata would be a
significant part of the filesystem image.  Usually metadata is close
enough to 0% to be mistaken for statistical noise.  So compressing it
makes a significant impact on an insignificant amount of data.

Jörn

-- 
One of my most productive days was throwing away 1000 lines of code.
-- Ken Thompson.

  reply	other threads:[~2008-08-22 17:19 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-08-21  5:45 [PATCH 04/10] AXFS: axfs_inode.c Jared Hulbert
2008-08-21  8:35 ` Carsten Otte
2008-08-21 11:35 ` Arnd Bergmann
2008-08-21 12:17 ` Arnd Bergmann
2008-08-21 15:06   ` Jared Hulbert
2008-08-21 15:12     ` Arnd Bergmann
2008-08-22  2:22   ` Phillip Lougher
2008-08-22  3:23     ` Jared Hulbert
2008-08-22  3:29       ` Phillip Lougher
2008-08-22 10:00     ` Arnd Bergmann
2008-08-22 17:08       ` Phillip Lougher
2008-08-22 17:19         ` Jörn Engel [this message]
2008-08-22 18:04           ` Jared Hulbert
2008-08-22  0:21 ` Phillip Lougher
2008-08-22  3:27   ` Jared Hulbert
2008-08-22  3:46     ` Phillip Lougher

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