From: tytso@mit.edu
Subject: Re: ext5
Date: Fri, 12 Feb 2010 11:02:43 -0500
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Cc: linux-ext4@vger.kernel.org
To: Ron Johnson <ron.l.johnson@cox.net>
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On Thu, Feb 11, 2010 at 10:47:15PM -0600, Ron Johnson wrote:
> On 2010-02-11 15:41, Goswin von Brederlow wrote:
> >tytso@mit.edu writes:
> >>The idea with read-only compressed files is that they are useful for
> >>large executables or large static files, where compressing them means
> >>that it takes less time to read them off of an HDD.
> >
> >Or when you only have so much flash.
> 
> Isn't that what squashfs is for?

The problem with the squashfs, fuse, ecryptfs approaches for the use
case that I am envisioning is that it's an all-or-nothing sort of
thing.  You may not want to encrypt all of the files in a file system.
Sure, you can play games with bind mounts, and/or accept the
performance hit of passing everything through fuse even for files that
aren't encrypted, but I think that's going to significantly inhibit
adoption of the technology.

Something which allows compressed and uncompressed files to co-exist
without any performance hits to the uncompressed files, and which
allows for a gradual transition after you upgrade rpm/dpkg and as
packages get upgraded is going to much easier time with adoption
rates.

							- Ted