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Date: Wed, 19 Sep 2007 04:16:44 +0200
From: Kurt Jaeger <lists@c0mplx.org>
To: Daichi GOTO <daichi@ongs.co.jp>
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Cc: freebsd-current@freebsd.org, freebsd-stable@freebsd.org
Subject: Re: Unionfs patchset p19 commit?
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Hi!

> >>I have a big hope to get merged into FreeBSD until
> >>7-RELEASE. Progress is step by step slowly, but going
> >>forward absolutely.  If you have interest in unionfs
> >>improvements, push your passion to re@ and fs@ committers ;-)
> >
> >Did you have a chance to look into this ?
> >
> >http://lists.freebsd.org/pipermail/freebsd-stable/2007-June/035798.html

> Already we have fixed above issue.
[...]

I'm compiling this patch on my test system right now.

Another issue is userland support for unionfs, e.g. in fstat,
as described on this page:

http://c0mplx.org/src/fstat-unionfs-patch/

Do you plan to analyse/investigate this topic ?

There's another topic if one uses unionfs in jail() setups: How to
backup the files, and only those files that a different from
the base ?

If I traverse a mounted unionfs, how do I know where data is coming
from, the lower mount or the higher mount ?

If I can't tell the difference, I'll backup quite a lot of stuff
multiple times.

I've experimented a little and found no easy way to tell lower
from upper unless I open the file (which sounds expensive). 
Have a look at http://c0mplx.org/src/isunionfs.c -- does this
sound like a way to go ?

-- 
pi@c0mplx.org           +49 171 3101372                        13 years to go !