From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailgw-01.dd24.net ([193.46.215.41]:36325 "EHLO mailgw-01.dd24.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756364AbcIYTyE (ORCPT ); Sun, 25 Sep 2016 15:54:04 -0400 Received: from mailpolicy-01.live.igb.homer.key-systems.net (mailpolicy-02.live.igb.homer.key-systems.net [192.168.1.27]) by mailgw-01.dd24.net (Postfix) with ESMTP id CEE095FF52 for ; Sun, 25 Sep 2016 19:54:00 +0000 (UTC) Received: from mailgw-01.dd24.net ([192.168.1.35]) by mailpolicy-01.live.igb.homer.key-systems.net (mailpolicy-02.live.igb.homer.key-systems.net [192.168.1.25]) (amavisd-new, port 10235) with ESMTP id n63lwSMJH6G5 for ; Sun, 25 Sep 2016 19:53:58 +0000 (UTC) Received: from [192.168.177.212] (51.red-81-38-116.dynamicip.rima-tde.net [81.38.116.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mailgw-01.dd24.net (Postfix) with ESMTPSA for ; Sun, 25 Sep 2016 19:53:58 +0000 (UTC) Message-ID: <1474833236.5905.1.camel@scientia.net> Subject: Re: Does data checksumming remain for files with No_COW file attribute? From: Christoph Anton Mitterer To: linux-btrfs@vger.kernel.org Date: Sun, 25 Sep 2016 21:53:56 +0200 In-Reply-To: <53bd018f-1d45-41e4-ef28-9fe632cf4002@inwind.it> References: <767591474719974@web21o.yandex.ru> <20160924174012.51d44caa@natsu> <20160924124323.GS7138@carfax.org.uk> <1474740691.7196.6.camel@scientia.net> <53bd018f-1d45-41e4-ef28-9fe632cf4002@inwind.it> Content-Type: multipart/signed; micalg="sha-512"; protocol="application/x-pkcs7-signature"; boundary="=-lkOfAHca7iuS8SmpOaTY" Mime-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org List-ID: --=-lkOfAHca7iuS8SmpOaTY Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sun, 2016-09-25 at 15:49 +0200, Goffredo Baroncelli wrote: > I think that the bigger cost is the lower performance due to the > write of checksums. Which would make btrfs default mode of CoW+checksumming also unusable... If for anyone checksumming comes at a too high cost, he can simply use=C2=A0nodatasum. 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