Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751842AbdGMMwT (ORCPT ); Thu, 13 Jul 2017 08:52:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:60671 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751165AbdGMMwS (ORCPT ); Thu, 13 Jul 2017 08:52:18 -0400 Date: Thu, 13 Jul 2017 14:52:12 +0200 From: Johannes Thumshirn To: Sagi Grimberg Cc: Christoph Hellwig , Keith Busch , mwilck@suse.de, Linux Kernel Mailinglist , Linux NVMe Mailinglist Subject: Re: [PATCH] nvmet: preserve controller serial number between reboots Message-ID: <20170713125212.GI5212@linux-x5ow.site> References: <20170713104806.12353-1-jthumshirn@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1484 Lines: 34 On Thu, Jul 13, 2017 at 03:30:39PM +0300, Sagi Grimberg wrote: > It seems weird that a subsystem has a serial. The subsystem is more of a hack I admit. But we don't maintain configurations for controllers in configfs, do we? > I'm not sure that a dynamic controller should maintain > a serial. Dynamic controllers by definition are allocated > on demand with no state of prior associations. But not sure > if a serial is a state (it probably isn't). The area is a little > fuzzy for me. I'm not certain as well, the only thing I know for sure currently is, it changes but we use in the standard 60-persistent-storage.rules [1] as a part of /dev/disk/by-id/nvme-$model-$serial-part%n [2] and I have a bit of a headace when users use it to identify their partitions in say /etc/fstab and the link changes as the target generated serial changes. Maybe we should consider this more as an RFD than a patch. I'm happy to withdraw if we find a better solution. [1] https://github.com/systemd/systemd/blob/master/rules/60-persistent-storage.rules [2] https://github.com/systemd/systemd/blob/master/rules/60-persistent-storage.rules#L27 Thanks, Johannes -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N?rnberg GF: Felix Imend?rffer, Jane Smithard, Graham Norton HRB 21284 (AG N?rnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850