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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3615ECAAD4 for ; Mon, 29 Aug 2022 22:10:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229469AbiH2WKy (ORCPT ); Mon, 29 Aug 2022 18:10:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229449AbiH2WKx (ORCPT ); Mon, 29 Aug 2022 18:10:53 -0400 Received: from mail104.syd.optusnet.com.au (mail104.syd.optusnet.com.au [211.29.132.246]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 640EA79EF6 for ; Mon, 29 Aug 2022 15:10:51 -0700 (PDT) Received: from dread.disaster.area (pa49-195-4-169.pa.nsw.optusnet.com.au [49.195.4.169]) by mail104.syd.optusnet.com.au (Postfix) with ESMTPS id 62DFB62DA00; Tue, 30 Aug 2022 08:10:49 +1000 (AEST) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1oSmxz-001UMJ-W0; Tue, 30 Aug 2022 08:10:48 +1000 Date: Tue, 30 Aug 2022 08:10:47 +1000 From: Dave Chinner To: Wang Yugui Cc: linux-xfs@vger.kernel.org Subject: Re: questions about hybird xfs wih ssd/hdd by realtime subvol Message-ID: <20220829221047.GU3600936@dread.disaster.area> References: <20220829102619.AE3B.409509F4@e16-tech.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220829102619.AE3B.409509F4@e16-tech.com> X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.4 cv=VuxAv86n c=1 sm=1 tr=0 ts=630d396a a=FOdsZBbW/tHyAhIVFJ0pRA==:117 a=FOdsZBbW/tHyAhIVFJ0pRA==:17 a=IkcTkHD0fZMA:10 a=biHskzXt2R4A:10 a=H0umD5oqAAAA:8 a=VwQbUJbxAAAA:8 a=FOH2dFAWAAAA:8 a=7-415B0cAAAA:8 a=jiEFvMsB7wAHyGiLJbAA:9 a=QEXdDO2ut3YA:10 a=oZNyUrSE6F0A:10 a=du2hvLAJtKcNxoDMbUSS:22 a=AjGcO6oz07-iQ99wixmX:22 a=i3VuKzQdj-NEYjvDI-p3:22 a=biEYGPWJfzWAr4FL6Ov7:22 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Mon, Aug 29, 2022 at 10:26:20AM +0800, Wang Yugui wrote: > Hi, > > I saw some info about hybird xfs wih ssd/hdd by realtime subvol. > > Hybrid XFS—Using SSDs to Supercharge HDDs at Facebook > https://www.usenix.org/conference/srecon19asia/presentation/shamasunder .... > Is there any tool/kernel option/kernel patch to control the data to save > into normal vol or realtime subvol firstly? FB were running a modified kernel that selected the rt dev based on the initial allocation size. Behaviour for them was predictable because they also controlled the application that was storing the data. See: https://lore.kernel.org/linux-xfs/20171128215527.2510350-1-rwareing@fb.com/ -Dave. -- Dave Chinner david@fromorbit.com