From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mr013msb.fastweb.it ([85.18.95.104]:39992 "EHLO mr013msb.fastweb.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751499AbeBZV2j (ORCPT ); Mon, 26 Feb 2018 16:28:39 -0500 Subject: Re: Reflink (cow) copy of busy files MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 26 Feb 2018 22:28:37 +0100 From: Gionatan Danti In-Reply-To: References: <9e69fcd01e1c02ea53e0e1ac66d60d24@assyoma.it> <20180224220757.GC30854@dastard> <711dd96e3c4b3e92d3fb38a01e77dc64@assyoma.it> <20180225024727.GD30854@dastard> <25ebcdb42650430d83d283435053efed@assyoma.it> <20180225211309.GF30854@dastard> <20180226002533.GG30854@dastard> <6eacd8faae2779b8dfb62fb0d65a9411@assyoma.it> <73ef828837683073feb1c49e3405dd6a@assyoma.it> Message-ID: <00a65dbb1d14b47fb92409db5e7d1e6e@assyoma.it> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Amir Goldstein Cc: Dave Chinner , linux-xfs , g.danti@assyoma.it Il 26-02-2018 21:29 Amir Goldstein ha scritto: > I was also expecting dirty data to be lost, but according to Darrick > that is > not the case for page cache dirty data, although in all likelyhook, > your VM > is using direct IO to write to image file. Yeah, it was better than expected. For some VM I use Qemu/KVM writeback policy rather than "none"/O_DIRECT, so the fact that host-side dirty data will not be lost when reflinking is a pleasant surprise. > I think your use case is interesting and this is definitely the right > place > to ask these questions. Great ;) -- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: g.danti@assyoma.it - info@assyoma.it GPG public key ID: FF5F32A8