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 D67A1C5ACC4 for ; Thu, 20 Feb 2020 03:41:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B5915206E2 for ; Thu, 20 Feb 2020 03:41:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727476AbgBTDlP (ORCPT ); Wed, 19 Feb 2020 22:41:15 -0500 Received: from mail104.syd.optusnet.com.au ([211.29.132.246]:60473 "EHLO mail104.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727506AbgBTDlP (ORCPT ); Wed, 19 Feb 2020 22:41:15 -0500 Received: from dread.disaster.area (pa49-195-185-106.pa.nsw.optusnet.com.au [49.195.185.106]) by mail104.syd.optusnet.com.au (Postfix) with ESMTPS id BC8E482026B; Thu, 20 Feb 2020 14:41:12 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1j4ci2-0005hm-Pk; Thu, 20 Feb 2020 14:41:06 +1100 Date: Thu, 20 Feb 2020 14:41:06 +1100 From: Dave Chinner To: Luis Chamberlain Cc: Richard Wareing , linux-xfs@vger.kernel.org, Anthony Iliopoulos Subject: Re: Modern uses of CONFIG_XFS_RT Message-ID: <20200220034106.GO10776@dread.disaster.area> References: <20200219135715.GZ30113@42.do-not-panic.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200219135715.GZ30113@42.do-not-panic.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=X6os11be c=1 sm=1 tr=0 a=bkRQb8bsQZKWSSj4M57YXw==:117 a=bkRQb8bsQZKWSSj4M57YXw==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=l697ptgUJYAA:10 a=7-415B0cAAAA:8 a=95owZCbt67vcucCyqxcA:9 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Wed, Feb 19, 2020 at 01:57:15PM +0000, Luis Chamberlain wrote: > I hear some folks still use CONFIG_XFS_RT, I was curious what was the > actual modern typical use case for it. I thought this was somewhat > realted to DAX use but upon a quick code inspection I see direct > realtionship. Facebook use it in production systems to separate large file data from metadata and small files. i.e. they use a small SSD based partition for the filesytem metadata and a spinning disk for the large scale data storage. Essentially simple teired storage. It's also commonly still used in multi-stream DVRs (think multi-camera security systems), and other similar sequential access data applications... That's just a couple off the top of my head... Cheers, Dave. -- Dave Chinner david@fromorbit.com