From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id D7890138239 for ; Fri, 19 Jul 2019 16:59:29 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 18D28E081A; Fri, 19 Jul 2019 16:59:24 +0000 (UTC) Received: from smtp.gentoo.org (smtp.gentoo.org [140.211.166.183]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id B60B2E07FE for ; Fri, 19 Jul 2019 16:59:23 +0000 (UTC) Received: from mail-ot1-f54.google.com (mail-ot1-f54.google.com [209.85.210.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: floppym) by smtp.gentoo.org (Postfix) with ESMTPSA id B016434803F for ; Fri, 19 Jul 2019 16:59:22 +0000 (UTC) Received: by mail-ot1-f54.google.com with SMTP id d17so33485166oth.5 for ; Fri, 19 Jul 2019 09:59:22 -0700 (PDT) X-Gm-Message-State: APjAAAV3km7OEJoq9WLxm9Ibd+a3cvS/iuu0/id+diiCU06Un7HzzkO2 RrIibPxC8w5IlbqnAwtAeDC2xeG+Me9XTslEyQA= X-Google-Smtp-Source: APXvYqx7hvcWuemOLLEnx3UhV4G0bwuC9v8Pcvn0CCyV1sx/h86oGajdHQ9m8bIbA+x1cWvpu73gHIgoU6AfamjY2J4= X-Received: by 2002:a9d:6014:: with SMTP id h20mr6939800otj.210.1563555560566; Fri, 19 Jul 2019 09:59:20 -0700 (PDT) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org X-Auto-Response-Suppress: DR, RN, NRN, OOF, AutoReply MIME-Version: 1.0 References: <6685853.amHapi50jO@localhost> <20190719163716.l6lkpnwlrcxg3353@matica.foolinux.mooo.com> In-Reply-To: <20190719163716.l6lkpnwlrcxg3353@matica.foolinux.mooo.com> From: Mike Gilbert Date: Fri, 19 Jul 2019 12:59:09 -0400 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [gentoo-user] Re: Using UUID for root disk in grub requires initramfs? To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset="UTF-8" X-Archives-Salt: 306d723b-009c-4cfa-845a-b5e048191e94 X-Archives-Hash: c7b69cd178d0639a7cbda0ae41eadb3f On Fri, Jul 19, 2019 at 12:37 PM Ian Zimmerman wrote: > > On 2019-07-19 20:58, Adam Carter wrote: > > > I experimented found the following worked in /etc/default/grub; > > > > GRUB_DEVICE="PARTUUID=d3554d49-02" > > > > Which writes grub.cfg as; > > linux /vmlinuz-5.2.0-gentoo root=PARTUUID=d3554d49-02 ro > > init=/usr/lib/systemd/systemd iommu=pt raid=noautodetect > > > > PARTUUID looked up with blkid. No initramfs required :) > > I don't get this. blkid is userspace. The _kernel_ needs to know what > the root fs device is, before it even starts pid 1. The kernel init code is able to find a device given its PARTUUID. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/init/do_mounts.c?h=v4.19.59#n172