From: Horst von Brand <vonbrand@inf.utfsm.cl>
To: "Jörn Engel" <joern@wohnheim.fh-wedel.de>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: unionfs
Date: Mon, 15 Mar 2004 15:22:41 -0400 [thread overview]
Message-ID: <200403151922.i2FJMfIh004411@eeyore.valparaiso.cl> (raw)
In-Reply-To: Message from =?iso-8859-1?Q?J=F6rn?= Engel <joern@wohnheim.fh-wedel.de> of "Mon, 15 Mar 2004 17:13:23 +0100." <20040315161323.GD16615@wohnheim.fh-wedel.de>
=?iso-8859-1?Q?J=F6rn?= Engel <joern@wohnheim.fh-wedel.de> said:
> On Mon, 15 March 2004 22:35:20 +0800, Ian Kent wrote:
> > I don't understand the requirement properly. Sorry.
> Depends on who you ask, but imo it boils down to this:
> - Use one filesystem as backing store, usually ro.
> - Have another filesystem on top for extra functionality, usually rw
> access.
>
> Famous example is a rw-CDROM, where writes go to hard drive and
> unchanged data is read from CDROM. But it makes sense for other
> things as well.
And what if the underlying filesystem is RW too? What should happen if you
unite several (>= 3) filesystems? What if some are RO, others RW? What do
you do if a file shows up several times, each different?
Assuming one RW on top of a RO only now: What should happen when a
file/directory is missing from the top? If the bottom one "shows through",
you can't delete anything; if it doesn't, you win nothing (because you will
have to keep a complete copy RW on top).
IIRC, this has been discussed a couple of times before, and the consensus
each time was that it isn't /that hard/ to do, it is /hard or impossible/
to find a sensible, simple semantics for this. The idea was then dropped...
--
Dr. Horst H. von Brand User #22616 counter.li.org
Departamento de Informatica Fono: +56 32 654431
Universidad Tecnica Federico Santa Maria +56 32 654239
Casilla 110-V, Valparaiso, Chile Fax: +56 32 797513
next prev parent reply other threads:[~2004-03-15 19:22 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-15 11:35 unionfs Carsten Otte
2004-03-15 12:19 ` unionfs Jörn Engel
2004-03-15 12:47 ` unionfs Ian Kent
2004-03-15 13:16 ` unionfs Jörn Engel
2004-03-15 14:35 ` unionfs Ian Kent
2004-03-15 16:13 ` unionfs Jörn Engel
2004-03-15 17:09 ` unionfs Claudio Martins
2004-03-15 19:22 ` Horst von Brand [this message]
2004-03-15 23:20 ` unionfs Chris Friesen
2004-03-16 16:04 ` unionfs Horst von Brand
2004-03-16 17:31 ` unionfs Jörn Engel
2004-03-16 18:04 ` unionfs Jörn Engel
2004-03-16 19:40 ` unionfs Horst von Brand
2004-03-16 20:45 ` unionfs Jörn Engel
2004-03-16 19:19 ` unionfs Horst von Brand
2004-03-16 20:00 ` unionfs Chris Friesen
2004-03-23 2:38 ` unionfs Robert White
2004-03-15 23:52 ` unionfs Jörn Engel
2004-03-16 16:18 ` unionfs Horst von Brand
2004-03-16 17:10 ` unionfs Jörn Engel
2004-03-19 9:11 ` unionfs Jamie Lokier
2004-03-19 9:42 ` unionfs Jörn Engel
2004-03-19 9:04 ` unionfs Jamie Lokier
2004-03-16 19:03 ` unionfs Andy Isaacson
2004-03-15 14:37 ` unionfs Ian Kent
2004-03-15 16:15 ` unionfs Jörn Engel
-- strict thread matches above, loose matches on Subject: below --
2004-03-08 9:52 unionfs Miklos Szeredi
2004-03-08 16:10 ` unionfs Bernd Schubert
2004-03-09 9:38 ` unionfs Miklos Szeredi
[not found] ` <20040311151343.GA943@escher.cs.wm.edu>
2004-03-11 15:44 ` unionfs Miklos Szeredi
2004-03-14 2:33 ` unionfs Ian Kent
2004-03-14 4:20 ` unionfs Horst von Brand
2004-03-16 12:42 ` unionfs Miklos Szeredi
[not found] ` <20040315214207.GA26615@escher.cs.wm.edu>
2004-03-16 13:43 ` unionfs Miklos Szeredi
2004-03-12 23:37 ` unionfs Herbert Poetzl
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=200403151922.i2FJMfIh004411@eeyore.valparaiso.cl \
--to=vonbrand@inf.utfsm.cl \
--cc=joern@wohnheim.fh-wedel.de \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).