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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 73D5FC7618B for ; Wed, 24 Jul 2019 10:08:54 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 49977218B8 for ; Wed, 24 Jul 2019 10:08:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 49977218B8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50232 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hqECb-0003J1-GP for qemu-devel@archiver.kernel.org; Wed, 24 Jul 2019 06:08:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57768) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hqECR-0002uW-5Q for qemu-devel@nongnu.org; Wed, 24 Jul 2019 06:08:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hqECP-0003zI-Pa for qemu-devel@nongnu.org; Wed, 24 Jul 2019 06:08:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55344) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hqECP-0003yu-HQ for qemu-devel@nongnu.org; Wed, 24 Jul 2019 06:08:41 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 927DD30C1341; Wed, 24 Jul 2019 10:08:40 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8807B60BCE; Wed, 24 Jul 2019 10:08:40 +0000 (UTC) Received: from zmail21.collab.prod.int.phx2.redhat.com (zmail21.collab.prod.int.phx2.redhat.com [10.5.83.24]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 7D34A1800202; Wed, 24 Jul 2019 10:08:40 +0000 (UTC) Date: Wed, 24 Jul 2019 06:08:40 -0400 (EDT) From: Pankaj Gupta To: Wei Yang Message-ID: <1511439706.4107561.1563962920125.JavaMail.zimbra@redhat.com> In-Reply-To: <20190724085308.GA12530@richard> References: <20190724070307.12568-1-richardw.yang@linux.intel.com> <1382557614.4041474.1563953302894.JavaMail.zimbra@redhat.com> <20190724085308.GA12530@richard> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.116.104, 10.4.195.11] Thread-Topic: docs/nvdimm: add example on persistent backend setup Thread-Index: An15nxNlCe0YM9Zu30gqn2V2AXsrSw== X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Wed, 24 Jul 2019 10:08:40 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH] docs/nvdimm: add example on persistent backend setup X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org, xiaoguangrong eric , mst@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" > > > >> > >> Persistent backend setup requires some knowledge about nvdimm and ndctl > >> tool. Some users report they may struggle to gather these knowledge and > >> have difficulty to setup it properly. > >> > >> Here we provide two examples for persistent backend and gives the link > >> to ndctl. By doing so, user could try it directly and do more > >> investigation on persistent backend setup with ndctl. > >> > >> Signed-off-by: Wei Yang > >> --- > >> docs/nvdimm.txt | 28 ++++++++++++++++++++++++++++ > >> 1 file changed, 28 insertions(+) > >> > >> diff --git a/docs/nvdimm.txt b/docs/nvdimm.txt > >> index b531cacd35..baba7a940d 100644 > >> --- a/docs/nvdimm.txt > >> +++ b/docs/nvdimm.txt > >> @@ -171,6 +171,32 @@ guest software that this vNVDIMM device contains a > >> region that cannot > >> accept persistent writes. In result, for example, the guest Linux > >> NVDIMM driver, marks such vNVDIMM device as read-only. > >> > >> +Backend File Setup Example > >> +.......................... > >> + > >> +Here is two examples for how to setup these persistent backend on > >> +linux, which leverages the tool ndctl [3]. > >> + > >> +It is easy to setup DAX device backend file. > >> + > >> +A. DAX device > >> + > >> + ndctl create-namespace -f -e namespace0.0 -m devdax > >> + > >> +The /dev/dax0.0 could be used directly in "mem-path" option. > >> + > >> +For DAX file, it is more than creating the proper namespace. The > >> +block device should be partitioned and mounted (with dax option). > >> + > >> +B. DAX file > >> + > >> + ndctl create-namespace -f -e namespace0.0 -m fsdax > >> + (partition /dev/pmem0 with name pmem0p1) > >> + mount -o dax /dev/pmem0p1 /mnt > >> + (dd a file with proper size in /mnt) > > > > Hi, Pankaj > > Thanks for your comment. > > >This namespace is for filesystem DAX? What if user wants to create namespace > >for > >device DAX to be used as persistent backend? > > > > User could choose the type (devdax/fsdax) in ndctl command line with -m > option. yes. > > >Does this makes sense to mention about by default namespace created on > >persistent > >backend? > > > > I don't get your point. Here is an example to let user know how to create > persistent backend. In case they want to get more control about the backend, > they can refer to the ndctl link. I agree this is helpful for users. > > You mean it is not proper to mention the backend setup example in the > document? We found many users come to us for how to setup it, so we decide to > add this section. Sorry! For some reason I ignored devicedax namespace information in patch. The patch looks good to me and I agree its helpful for the users. Thanks, Pankaj > > Do you have other option? > > >Thanks, > >Pankaj > > > >> + > >> +Then the new file in /mnt could be used in "mem-path" option. > >> + > >> NVDIMM Persistence > >> ------------------ > >> > >> @@ -212,3 +238,5 @@ References > >> https://www.snia.org/sites/default/files/technical_work/final/NVMProgrammingModel_v1.2.pdf > >> [2] Persistent Memory Development Kit (PMDK), formerly known as NVML > >> project, home page: > >> http://pmem.io/pmdk/ > >> +[3] ndctl-create-namespace - provision or reconfigure a namespace > >> + http://pmem.io/ndctl/ndctl-create-namespace.html > >> -- > >> 2.17.1 > >> > >> > >> > > -- > Wei Yang > Help you, Help me > >