From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 2C64913800E for ; Sun, 12 Aug 2012 12:27:53 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id EDB3BE04C1; Sun, 12 Aug 2012 12:27:13 +0000 (UTC) Received: from mail-bk0-f53.google.com (mail-bk0-f53.google.com [209.85.214.53]) by pigeon.gentoo.org (Postfix) with ESMTP id B576AE0369 for ; Sun, 12 Aug 2012 12:25:24 +0000 (UTC) Received: by bkwj4 with SMTP id j4so1267041bkw.40 for ; Sun, 12 Aug 2012 05:25:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; bh=R6UYlA2J+Hc2fhrq5ORp+neQB66CLGe5yx7RhdtJLJM=; b=oOHrIiG12lmKzM76h2cUmTPXs83cuPbAL7H3dyXLhUW15Vh9GtlRS2N58zu0CHLYsI OGr1JKPMvyWERlzL3TIRWu3OznbRdurI6c04CmXdkl2XuNbDe5lWBc6baIrMzst58hn1 7goHzX9OsAP2fxrkWNcpzoE0yFTsAvQl5Nq/cmoT5Xdg9oToIcg3YsdQTKBJLCBlAhpt T1QY9xGx5Q2XOIt+yLuOuguHD3Olfzu2StkIaEGso9t8Q660JH7r8a7CQdhJBRO7oeWt zgr2+sfzELOl5xbZVjtkda/d2cbg02y6yRtK9BI7WbXsZAZil2EijzMWr0J+Q74Uuvbf wlGQ== Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-dev@lists.gentoo.org Reply-to: gentoo-dev@lists.gentoo.org MIME-Version: 1.0 Received: by 10.204.154.215 with SMTP id p23mr3039571bkw.53.1344774323597; Sun, 12 Aug 2012 05:25:23 -0700 (PDT) Sender: freemanrich@gmail.com Received: by 10.205.82.12 with HTTP; Sun, 12 Aug 2012 05:25:23 -0700 (PDT) In-Reply-To: References: <5026EAE7.4040600@gmail.com> <20120812001239.27781.qmail@stuge.se> Date: Sun, 12 Aug 2012 08:25:23 -0400 X-Google-Sender-Auth: wZbKccLPtnTIUzH0HP9Q09bnbQk Message-ID: Subject: Re: [gentoo-dev] Re: Questions about SystemD and OpenRC From: Rich Freeman To: gentoo-dev@lists.gentoo.org Content-Type: text/plain; charset=ISO-8859-1 X-Archives-Salt: c7298cd7-5720-4d1e-8ad9-e9bc008f9692 X-Archives-Hash: 5cf9a5a734051947e7335bd27f81aba8 On Sun, Aug 12, 2012 at 5:43 AM, Duncan <1i5t5.duncan@cox.net> wrote: > Peter Stuge posted on Sun, 12 Aug 2012 02:12:38 +0200 as excerpted: >> >> What software parses the filesystem labels when you boot with openrc? >> >> (I ask because I never use labels myself.) > > Short answer, mount and udev, and the kernel directly when fed that > information for root= on the kernel commandline. >... > It'a also worth noting that the kernel's root= line can take a number of > these (I'm not sure if it can take them all), including partlabel, > according to information someone posted on the btrfs list I'm pretty sure that this particular part of your post is incorrect, but I'd be happy to be corrected. The kernel cannot interpret a root= parameter that doesn't reference a device node that it can't internally generate (with a devtmpfs/etc). I'm pretty sure that rules out just about anything but a physical device (not even /dev/by-uuid/...). I think that people get this confused because 99% of linux users have an initramfs (and about 2% of Gentoo users it seems), and most initramfs implementations DO interpret the root=parameter. If you specify an initramfs then the kernel actually ignores the root=parameter entirely, mounting the initramfs as root, and passing control to its init. The initramfs is expected to mount root (or not - you could just run the whole system off an initramfs I guess). Most initramfs implementations just parse the root= line on the kernel, although it is worth noting that genkernel's initramfs does not and uses real_root instead. So, I could see how many linux users might think that interpreting a complex root= parameter is a kernel function, when it is really just the fact that they use an initramfs. If somebody is running with root=LABEL=foo or something like that without an initramfs I'll happily stand corrected. Rich