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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 46C8EC433E0 for ; Thu, 28 Jan 2021 20:30:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E76AC6146D for ; Thu, 28 Jan 2021 20:29:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229817AbhA1U3n (ORCPT ); Thu, 28 Jan 2021 15:29:43 -0500 Received: from mx2.suse.de ([195.135.220.15]:57958 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229595AbhA1U3j (ORCPT ); Thu, 28 Jan 2021 15:29:39 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A88D5B130; Thu, 28 Jan 2021 20:28:57 +0000 (UTC) Date: Thu, 28 Jan 2021 21:28:56 +0100 From: David Disseldorp To: Roman Bolshakov Cc: Dmitry Bogdanov , Martin Petersen , , , Subject: Re: [PATCH v2] scsi: target: core: check SR field in REPORT LUNS Message-ID: <20210128212856.1f1117e6@suse.de> In-Reply-To: References: <20210120102700.5514-1-d.bogdanov@yadro.com> <20210122234251.595d5b7a@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi Roman, On Tue, 26 Jan 2021 12:13:44 +0300, Roman Bolshakov wrote: > Hi David, > > SELECT REPORT field can be used for vVOL (LU conglomerate) discovery and > for well-known lun listing. > > The field is used by VMware ESXi: > https://support.purestorage.com/Solutions/VMware_Platform_Guide/User_Guides_for_VMware_Solutions/Virtual_Volumes_User_Guide/vVols_User_Guide%3A_Protocol_Endpoints > > "PEs greatly extend the number of vVols that can be connected to an ESXi > cluster; each PE can have up to 16,383 vVols per host bound to it > simultaneously. Moreover, a new binding does not require a complete I/O > rescan. Instead, ESXi issues a REPORT_LUNS SCSI command with SELECT > REPORT to the PE to which the sub-lun is bound. The PE returns a list of > sub-lun IDs for the vVols bound to that host. In large clusters, > REPORT_LUNS is significantly faster than a full I/O rescan because it is > more precisely targeted." Interesting, thanks. ... > With regards to bumping TCM to SPC-4, are there any objections if we > submit a separate patch for that? Or resubmit a series with the patch? I don't object to that. FWIW, the following crude metrics could be seen as an argument in favour of SPC-4 versioning: linux> git grep -ic -e "SPC4" -e "SPC-4" -- drivers/target/ drivers/target/target_core_alua.c:7 drivers/target/target_core_alua.h:5 drivers/target/target_core_device.c:1 drivers/target/target_core_fabric_lib.c:5 drivers/target/target_core_pr.c:37 drivers/target/target_core_spc.c:19 drivers/target/target_core_tmr.c:3 drivers/target/target_core_transport.c:2 drivers/target/target_core_ua.c:1 drivers/target/target_core_ua.h:1 drivers/target/target_core_xcopy.c:3 drivers/target/target_core_xcopy.h:1 linux> git grep -ic -e "SPC3" -e "SPC-3" -- drivers/target/ drivers/target/target_core_alua.c:1 drivers/target/target_core_configfs.c:14 drivers/target/target_core_pr.c:75 drivers/target/target_core_spc.c:4 drivers/target/target_core_tmr.c:1 drivers/target/target_core_transport.c:4 drivers/target/target_core_ua.c:1 Most of the SPC3 target_core_pr and target_core_configfs matches above are debug/error messages, rather than spec references. Cheers, David