Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 30 Oct 2000 18:37:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 30 Oct 2000 18:37:24 -0500 Received: from neon-gw.transmeta.com ([209.10.217.66]:37640 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id ; Mon, 30 Oct 2000 18:37:11 -0500 Message-ID: <39FE061D.A68170B1@transmeta.com> Date: Mon, 30 Oct 2000 15:37:01 -0800 From: "H. Peter Anvin" Organization: Transmeta Corporation X-Mailer: Mozilla 4.75 [en] (X11; U; Linux 2.4.0-test10-pre3 i686) X-Accept-Language: en, sv, no, da, es, fr, ja MIME-Version: 1.0 To: David Woodhouse CC: linux-kernel@vger.kernel.org Subject: Re: / on ramfs, possible? In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org David Woodhouse wrote: > > On Mon, 30 Oct 2000, H. Peter Anvin wrote: > > > Pardon?! This doesn't make any sense... > > > > The question was: how do switch from the initrd to using the ramfs as /? > > Using pivot_root should do it (after the pivot, you can of course nuke > > the initrd ramdisk.) > > My question is: What do you want to do that for? You can nuke the initrd > ramdisk, but you can't drop the rd.c code, or ll_rw_blk.c code, etc. So > why not just keep your root filesystem in the initrd where it started off? > Umm... because the size of a ramdisk is fixed, but the size of a ramfs is flexible? I can certainly understand this problem... I might in fact do exactly this in the next version of my SuperRescue disk. There, the ramdisk which is the real root is populated from a .tar.gz file; the initrd is just there to unpack the .tar.gz file onto the "real" ramdisk; the initrd is then jettisoned. Why not just have the real root be the initrd, you ask? It's too large: since an initrd needs to exist in both compressed form and uncompressed form in memory at the same time; it would mean SuperRescue would no longer work on systems with 64 MB RAM. If I went to ramfs it might actually work on systems with 48 MB RAM, albeit you better not need to much space in / (or conversely, it would suddenly let you put a whole lot more stuff in /tmp if you have 512 MB.) -hpa -- at work, in private! "Unix gives you enough rope to shoot yourself in the foot." http://www.zytor.com/~hpa/puzzle.txt - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/