From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED1B0C04AAF for ; Thu, 16 May 2019 14:07:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C84B3205C9 for ; Thu, 16 May 2019 14:07:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726717AbfEPOHq (ORCPT ); Thu, 16 May 2019 10:07:46 -0400 Received: from mx2.suse.de ([195.135.220.15]:39230 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726703AbfEPOHq (ORCPT ); Thu, 16 May 2019 10:07:46 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 2BC81AF2A; Thu, 16 May 2019 14:07:44 +0000 (UTC) Subject: Re: Block device naming To: Alibek Amaev Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org References: From: Hannes Reinecke Message-ID: <680c9440-f1c9-68d1-cc5a-17aa9071fcc1@suse.de> Date: Thu, 16 May 2019 16:07:43 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 5/16/19 3:49 PM, Alibek Amaev wrote: > I have more example from IRL: > In Aug 2018 I was start server with attached storages by FC from ZS3 > and ZS5 (it is Oracle ZFS Storage Appliance, not NetApp and also > export space as LUN) server use one LUN from ZS5. And recently on > server stopped all IO on this exported LUN and io-wait is grow, in > dmesg no any errors or any changes about FC, no errors in > /var/log/kern.log* /var/log/syslog.log*, no throttling, no edac errors > or other. > But before reboot I saw: > wwn-0x600144f0b49c14d100005b7af8ee001c -> ../../sdc > I try to run partprobe or try to copy from this block device some data > to /dev/null by dd - operations wasn't finished IO is blocked > And after reboot i seen: > wwn-0x600144f0b49c14d100005b7af8ee001c -> ../../sdd > And server is run ok. > > Also I have LUN exported from storage in shared mode and it accesible > for all servers by FC. Currently this LUN not need, but now I doubt it > is possible to safely remove it... > It's all a bit conjecture at this point. 'sdc' could be show up as 'sdd' after the next reboot, with no side-effects whatsoever. At the same time, 'sdc' could have been blocked by a host of reasons, none of which are related to the additional device being exported. It doesn't really look like an issue with device naming; you would need to do proper investigation on your server to figure out why I/O stopped. Device renaming is typically the least likely cause here. Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg)