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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 EDE1CC32771 for ; Sat, 18 Jan 2020 23:06:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BCFB62469C for ; Sat, 18 Jan 2020 23:06:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="XaEAqY7c" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727012AbgARXGj (ORCPT ); Sat, 18 Jan 2020 18:06:39 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:52304 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727008AbgARXGj (ORCPT ); Sat, 18 Jan 2020 18:06:39 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 00IMwjdS105976; Sat, 18 Jan 2020 23:06:36 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2019-08-05; bh=7u5eK+FvIX6ULRP9b8ougFE9Od0bvaDt/x/0hZNUplU=; b=XaEAqY7caBSEQSrBTiNbyuBzl7Eh9bOQXHnyXq4FNzAt40uKqxn0YZPaRERTNMKuhfjC 1mS4OWbL/vgCBsPKxY7WTP8fh+fx9Nhy99dVOHeFjRk17BVHp2FCwebfm2RczokUGxim M7bxau32ZKeolbXJa87QU5tHP3Fzg+NZqejOAQRzBl+xsNL8hhXt7deueIeDSCvZR0oK ikzdMflTrPt6oaJnIYdYTWAdRNr/1G2QYAlhYglH4CFRFhHgWEQKZziPBXmx2tIpgBtz jkj8/KkX/45uIYZ/h8VaDvQ+Z5jb3e5R3TUjf6i9k1dhr00RzYWhqAsH81p1dd/qx1YU Aw== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 2xkseu25nt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 18 Jan 2020 23:06:35 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 00IN0klH150322; Sat, 18 Jan 2020 23:06:35 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3030.oracle.com with ESMTP id 2xkr2dbcyq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 18 Jan 2020 23:06:35 +0000 Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 00IN6Xo3001887; Sat, 18 Jan 2020 23:06:33 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Sat, 18 Jan 2020 15:06:32 -0800 Date: Sat, 18 Jan 2020 15:06:31 -0800 From: "Darrick J. Wong" To: Gionatan Danti Cc: linux-xfs@vger.kernel.org Subject: Re: XFS reflink vs ThinLVM Message-ID: <20200118230631.GX8247@magnolia> References: <20200113165341.GE8247@magnolia> <20200113180914.GI8247@magnolia> <8e96231f-8fc6-b178-9e83-84cbb9af6d2e@assyoma.it> <9d8e8614-9ae1-30ee-f2b4-1e45b90b27f8@assyoma.it> <20200115163948.GF8257@magnolia> <761fcf8f9d68ee221a35d15c1a7120c5@assyoma.it> <20200117234219.GM8257@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9504 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001180186 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9504 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001180186 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Sat, Jan 18, 2020 at 12:08:48PM +0100, Gionatan Danti wrote: > Il 18-01-2020 00:42 Darrick J. Wong ha scritto: > > How many fragments, and how big of a sparse file? > > A just installed CentOS 8 guest using a 20 GB sparse file vdisk had about > 2000 fragments. > > After running "fio --name=test --filename=test.img --rw=randwrite --size=4G" 4GB / 1M extents == 4096, which is probably the fs blocksize :) I wonder, do you get different results if you set an extent size hint on the dir before running fio? I forgot(?) to mention that if you're mostly dealing with sparse VM images then you might as well set a extent size hint and forego delayed allocation because it won't help you much. --D > for about 30 mins, it ended with over 1M fragments/extents. At that point, > reflinking that file took over 2 mins, and unlinking it about 4 mins. > > I understand fio randwrite pattern is a worst case scenario; still, I think > the results are interesting and telling for "aged" virtual machines. > > As a side note, a just installed Win2019 guest backed with an 80 GB sparse > file had about 18000 fragments. > 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