From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from outrelay08.libero.it ([212.52.84.112]:42350 "EHLO outrelay08.libero.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752435AbaCJWiZ (ORCPT ); Mon, 10 Mar 2014 18:38:25 -0400 Message-ID: <531E3F10.3000908@libero.it> Date: Mon, 10 Mar 2014 23:39:12 +0100 From: Goffredo Baroncelli Reply-To: kreijack@inwind.it MIME-Version: 1.0 To: systemd-devel@lists.freedesktop.org, linux-btrfs Subject: Re: [systemd-devel] [HEADS-UP] Discoverable Partitions Spec References: <20140307182603.GA22874@tango.0pointer.de> <531E059B.1010509@libero.it> <20140310200228.GA18268@tango.0pointer.de> In-Reply-To: <20140310200228.GA18268@tango.0pointer.de> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 03/10/2014 09:02 PM, Lennart Poettering wrote: > On Mon, 10.03.14 19:34, Goffredo Baroncelli (kreijack@libero.it) wrote: > > Heya, > >> Instead of relying on the subvolume UUID, why not relying to the subvolume name: it would be more simple and flexible to manage them. >> >> For example supposing to use '@' as prefix for a subvolume name: >> >> @ -> root filesystem >> @etc -> etc >> @home -> home >> [...] > > Well, the name is property of the admin really. There needs to be a way > how the admin can label his subvolumes, with a potentially localized > name. This makes it unsuitable for our purpose, we cannot just take > possession of this and leave the admin with nothing. Instead of the name we can use the xattr to store these information. > On GPT there are also gpt partition labels and partition types. The > former are property of the admin, he can place there whatever he wants, > in whatever language he chooses... The latter however is how we make > sense of it on a semantical level. > >> Or in another way we could group the different systems in subdirectories: >> >> @home -> home of all the systems >> @srv -> srv of all the systems >> fedora/@ -> root of a fedora system >> fedora/@etc -> etc of the fedora system >> fedora2/@ -> root of a fedora2 system >> fedora2/@etc -> etc of the fedora2 system > > I am pretty sure automatic discovery of mount points should not cover > the usecase where people install multiple distributions into the same > btrfs volume. THe automatic logic should cover the simple cases only, > and it sounds way over the top to support installing multiple OSes into > the same btrfs... I mean, people can do that, if they want to, they just > have to write a proper fstab, which I think is not too much too ask... In your specification, you referred the use case of "container" (via nspawn / libvrt-lxc). which have to boot "a disk image". Why you don't mind to use a container on a btrfs snapshot ? I think that it will be reasonable to have different containers on a snapshots of the same filesystem-tree. > > Lennart > -- gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5