From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Doffman Subject: Re: [PATCH v3 0/2] Add ceph root filesystem Date: Thu, 05 Jun 2014 14:13:31 -0500 Message-ID: <5390C15B.4060407@codethink.co.uk> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from ducie-dc1.codethink.co.uk ([185.25.241.215]:37713 "EHLO ducie-dc1.codethink.co.uk" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752110AbaFETNk (ORCPT ); Thu, 5 Jun 2014 15:13:40 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Alex Elsayed , ceph-devel@vger.kernel.org On 05/28/2014 06:46 PM, Alex Elsayed wrote: > mark.doffman@codethink.co.uk wrote: > >> From: Mark Doffman >> >> Hi All, >> >> The following is a third version of a patch series that adds the ability >> to use a ceph distributed file system as the root device. > > > Would you mind expanding on why you want to do this in the kernel, instead > of using an initramfs? For example, dracut supports the following syntax, > and sets it up using the same tools as mounting NFS in a running system > rather than the kernel's nfsroot support: > > root=nfs:[:][:] > root=nfs4:[:][:] > root={dhcp|dhcp6} > > root=dhcp alone directs initrd to look at the DHCP root-path where NFS > options can be specified. > > It also supports CIFS, as a further illustration: > > root=cifs://[[:]@]: > > Extending this to Ceph seems much simpler than implementing such a thing in > the kernel, especially given dracut's modular nature, and it's easy enough > to compile an initramfs into the kernel. An initramfs, and dracut, has been mentioned before as a possible solution. The reason I would prefer this in the kernel is simplicity. NFS root is in the kernel and we regularly use it without an initramfs. However simple dracut is still a more complex procedure, for something that is very easy to do in the kernel. Using a root device also has the advantage that it might produce smaller images for memory constrained devices. > > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >