From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.gentoo.org ([140.105.134.102] helo=robin.gentoo.org) by nuthatch.gentoo.org with esmtp (Exim 4.54) id 1EnOED-00010o-FF for garchives@archives.gentoo.org; Fri, 16 Dec 2005 22:39:05 +0000 Received: from robin.gentoo.org (localhost [127.0.0.1]) by robin.gentoo.org (8.13.5/8.13.5) with SMTP id jBGMceRk023476; Fri, 16 Dec 2005 22:38:40 GMT Received: from mout1.freenet.de (mout1.freenet.de [194.97.50.132]) by robin.gentoo.org (8.13.5/8.13.5) with ESMTP id jBGMceXs029691 for <gentoo-osx@lists.gentoo.org>; Fri, 16 Dec 2005 22:38:40 GMT Received: from [194.97.55.148] (helo=mx5.freenet.de) by mout1.freenet.de with esmtpa (Exim 4.60) (envelope-from <dirk.schoenberger@sz-online.de>) id 1EnODo-0001Yf-9Z for gentoo-osx@lists.gentoo.org; Fri, 16 Dec 2005 23:38:40 +0100 Received: from p54b31437.dip0.t-ipconnect.de ([84.179.20.55] helo=rincewind) by mx5.freenet.de with esmtpa (ID dirk.schoenberger@freenet.de) (Exim 4.60 #3) id 1EnODo-0004Ui-1D for gentoo-osx@lists.gentoo.org; Fri, 16 Dec 2005 23:38:40 +0100 Message-ID: <00f501c60291$2d02a7a0$14b2a8c0@rincewind> From: =?iso-8859-1?Q?Dirk_Sch=F6nberger?= <dirk.schoenberger@sz-online.de> To: <gentoo-osx@lists.gentoo.org> References: <59205.84.179.205.179.1134746227.squirrel@mail.sz-online.de> <20051216152450.GU4481@gentoo.org> <58032.84.179.205.179.1134747031.squirrel@mail.sz-online.de> <20051216174036.GW14948@gentoo.org> <00b701c60284$146d8be0$14b2a8c0@rincewind> <20051216221614.GZ14948@gentoo.org> Subject: Re: [gentoo-osx] New document: Project targets Date: Fri, 16 Dec 2005 23:36:28 +0100 Precedence: bulk List-Post: <mailto:gentoo-osx@lists.gentoo.org> List-Help: <mailto:gentoo-osx+help@gentoo.org> List-Unsubscribe: <mailto:gentoo-osx+unsubscribe@gentoo.org> List-Subscribe: <mailto:gentoo-osx+subscribe@gentoo.org> List-Id: Gentoo Linux mail <gentoo-osx.gentoo.org> X-BeenThere: gentoo-osx@gentoo.org Reply-to: gentoo-osx@lists.gentoo.org MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2014.211 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2014.211 X-Warning: sz-online.de is listed at abuse.rfc-ignorant.org X-Archives-Salt: 253c1c85-280b-482e-b738-4ee7604c3d31 X-Archives-Hash: ba7d9a198a6f107daed5063072ee2546 > How does the absense of a read-only file-system affect the ability to > have a union-mount only 'visible' for a specific user or user-process? > Or is this read-only thing necessary to solve another problem? > Essential for the union-mount solution to work, is that it can at > least be *only* visible/available for a given (user) process. Otherwise > your system is less different from a progressive system. Still in that > case, the union-mount solution might have some advantages, like simple > repair, and a backup procedure (unmount the union-mount, or restart the > machine -- assuming you didn't add the union-mount to fstab). The idea seems to be that you have a "live" version of the host system (real "/", which is mounted read-only and unioned with a copy on write system). Current Darwin only allows .dmg or mounting from an unmounted device. In both cases the underlying system is intrinsically read-only, i.e. the union fs is not really needed. I don't think it is a good idea to unomount / remount read-only your root file system. If you clone a existing installation and mount this, I think you have effectively a progressive system. This approach is mentioned in the entoo-macos bootstrap howto. That the union file system is visible to all processes becomes a secondary problem (I think it just means that you could have only one parallel Gentoo union / chroot) The basic problem with the Darwin unionfs implementation is that you have to have a (read-only) file system in the first place, which you can union to. As far as I understand the Linux version (which may be only a wishlist entry resp. a specification, you can do things like mount folder1 read-only U folder2 read-only U folder 3 read-write (where U is a concatenation operator) The FreeBSD soltuins divides these usecases into the actual union (unionfs), and the mount from a subfolder of a mounted deice (nullfs) Regards Dirk -- gentoo-osx@gentoo.org mailing list