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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 D8FBBC33CB1 for ; Tue, 14 Jan 2020 08:58:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B576B2075B for ; Tue, 14 Jan 2020 08:58:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726121AbgANI61 (ORCPT ); Tue, 14 Jan 2020 03:58:27 -0500 Received: from mr011msb.fastweb.it ([85.18.95.108]:40514 "EHLO mr011msb.fastweb.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725860AbgANI61 (ORCPT ); Tue, 14 Jan 2020 03:58:27 -0500 Received-SPF: pass (mr011msb.fastweb.it: domain assyoma.it designates 93.63.55.57 as permitted sender) identity=mailfrom; receiver=mr011msb.fastweb.it; client-ip=93.63.55.57; envelope-from=g.danti@assyoma.it; helo=ceres.assyoma.it; X-RazorGate-Vade: gggruggvucftvghtrhhoucdtuddrgedufedrvdejuddguddvfecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfhtefuvfghgfeupdcuqfgfvfenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepuffvfhfhohfkffgfgggjtgfgsehtjeertddtfeejnecuhfhrohhmpefiihhonhgrthgrnhcuffgrnhhtihcuoehgrdgurghnthhisegrshhshihomhgrrdhitheqnecuffhomhgrihhnpegrshhshihomhgrrdhithenucfkphepleefrdeifedrheehrdehjeenucfrrghrrghmpehhvghloheptggvrhgvshdrrghsshihohhmrgdrihhtpdhinhgvthepleefrdeifedrheehrdehjedpmhgrihhlfhhrohhmpeeoghdruggrnhhtihesrghsshihohhmrgdrihhtqecuuefqffgjpeekuefkvffokffogfdprhgtphhtthhopeeouggrrhhrihgtkhdrfihonhhgsehorhgrtghlvgdrtghomhequcfqtfevrffvpehrfhgtkedvvdenuggrrhhrihgtkhdrfihonhhgsehorhgrtghlvgdrtghomhdprhgtphhtthhopeeolhhinhhugidqgihfshesvhhgvghrrdhkvghrnhgvlhdrohhrghequcfqtfevrffvpehrfhgtkedvvdenlhhinhhugidqgihfshesvhhgvghrrdhkvghrnhgvlhdrohhrghenucevlhhushhtvghrufhiiigvpedt X-RazorGate-Vade-Verdict: clean 0 X-RazorGate-Vade-Classification: clean Received: from ceres.assyoma.it (93.63.55.57) by mr011msb.fastweb.it (5.8.208) id 5E19B4DB00328269; Tue, 14 Jan 2020 09:45:20 +0100 Received: from gdanti-lenovo.assyoma.it (unknown [172.31.255.5]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by ceres.assyoma.it (Postfix) with ESMTPSA id 00DEC265489; Tue, 14 Jan 2020 09:45:19 +0100 (CET) Subject: Re: XFS reflink vs ThinLVM To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org References: <20200113111025.liaargk3sf4wbngr@orion> <703a6c17-cc02-2c2c-31ce-6cd12a888743@assyoma.it> <20200113114356.midcgudwxpze3xfw@orion> <627cb07f-9433-ddfd-37d7-27efedd89727@assyoma.it> <39b50e2c-cb78-3bcd-0130-defa9c573b71@assyoma.it> <20200113165341.GE8247@magnolia> <20200113180914.GI8247@magnolia> From: Gionatan Danti Organization: Assyoma s.r.l. Message-ID: <8e96231f-8fc6-b178-9e83-84cbb9af6d2e@assyoma.it> Date: Tue, 14 Jan 2020 09:45:19 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: <20200113180914.GI8247@magnolia> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: it Content-Transfer-Encoding: 7bit Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On 13/01/20 19:09, Darrick J. Wong wrote: > xfs_io -c 'bmap -c -e -l -p -v ' test.img Ok, good to know. Thanks. > If you are interested in online scrub, then I'd say yes because it's the > secret sauce that gives online metadata checking most of its power. I > confess, I haven't done a lot of performance analysis of rmap lately, > the metadata ops overhead might still be in the ~10% range. > > The two issues preventing rmap from being turned on by default (at least > in my head) are (1) scrub itself is still EXPERIMENTAL and (2) it's not > 100% clear that online fsck is such a killer app that everyone will want > it, since you always pay the performance overhead of enabling rmap > regardless of whether you use xfs_scrub. Well, I really think online scrub, when ready, will be a killer feature. So, for a "mere" 10% performance penalty, I would enable rbmap unless a concrete chance to expose some bug exists. Thanks. -- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: g.danti@assyoma.it - info@assyoma.it GPG public key ID: FF5F32A8