Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1424564AbWLBWzm (ORCPT ); Sat, 2 Dec 2006 17:55:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1424586AbWLBWzl (ORCPT ); Sat, 2 Dec 2006 17:55:41 -0500 Received: from 1wt.eu ([62.212.114.60]:19461 "EHLO 1wt.eu") by vger.kernel.org with ESMTP id S1424557AbWLBWzk (ORCPT ); Sat, 2 Dec 2006 17:55:40 -0500 Date: Sat, 2 Dec 2006 23:55:28 +0100 From: Willy Tarreau To: Jan Engelhardt Cc: William Estrada , linux-kernel@vger.kernel.org Subject: Re: Mounting NFS root FS Message-ID: <20061202225528.GA27342@1wt.eu> References: <4571CE06.4040800@popdial.com> <20061202211522.GB24090@1wt.eu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2059 Lines: 55 On Sat, Dec 02, 2006 at 10:56:38PM +0100, Jan Engelhardt wrote: > > >> > I have been trying to make FC5's kernel do a boot with an NFS root file > >> > system. I see > >> > the support is in the kernel(?). I have tried this: > >> > > >> >> root=/dev/nfs nfsroot=10.1.1.12:/tftpboot/NFS/Root_FS > >> > >> This feature is almost deprecated. One is supposed to use initramfs, > >> /sbin/ip or some DHCP client, and a mount program nowadays. > > > >But I think that there are plenty of light terminals still booting like > >this which will not be able to upgrade anymore then. Even right here, > >my web server (parisc) boot from the network that way. At least an > >initramfs would need to be able to cope with the same syntax, > > No problem: > > << #!/bin/bash > > for o in `cat /proc/cmdline`; do > case "$o" in > nfsroot=*) > arg="${o##nfsroot=}"; > ;; > esac; > done; > > ### further parse $arg > >>> > > simplified example of how this can be accomplished. This is why > initrds/initramfs are so much more powerful than in-kernel software. I'm not saying initramfs is not powerful, and indeed your example is the common way of parsing cmdline for me too. What I'm saying is that before nfsroot stops being supported, we'll need a working replacement (and not "### further parse $arg"), if possible within the kernel tree so that people who used to build kernels to boot such machines will still be able to build kernels for them, even if this implies using an initramfs with some tools in it. The real danger of removing support for in-kernel features like this is to leave people with no solution at all (because they don't know how to proceed), and their workarounds are often worse than the problem that we tried to fix in the first place. Willy - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/