From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:49079 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751268AbbLQFNB (ORCPT ); Thu, 17 Dec 2015 00:13:01 -0500 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1a9Qs6-0004FR-VJ for linux-btrfs@vger.kernel.org; Thu, 17 Dec 2015 06:12:58 +0100 Received: from ip98-167-165-199.ph.ph.cox.net ([98.167.165.199]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 17 Dec 2015 06:12:58 +0100 Received: from 1i5t5.duncan by ip98-167-165-199.ph.ph.cox.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 17 Dec 2015 06:12:58 +0100 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: [auto-]defrag, nodatacow - general suggestions?(was: btrfs: poor performance on deleting many large files?) Date: Thu, 17 Dec 2015 05:12:51 +0000 (UTC) Message-ID: References: <56530DAD.9080607@gmail.com> <1448497439.28195.33.camel@scientia.net> <5667C00B.4010100@scientia.net> <1450303141.6242.50.camel@scientia.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Christoph Anton Mitterer posted on Wed, 16 Dec 2015 22:59:01 +0100 as excerpted: >> he obviously didn't think thru the fact that compression MUST be a >> rewrite, thereby breaking snapshot reflinks, even were normal >> non-compression defrag to be snapshot aware, because compression >> substantially changes the way the file is stored), that's _implied_, >> not explicit. > So you mean, even if ref-link aware defrag would return, it would still > break them again when compressing/uncompressing/recompressing? > I'd have hoped that then, all snapshots respectively other reflinks > would simply also change to being compressed, You're correct. I "obviously didn't thing thru" that the whole way, myself. =:^( But meanwhile, we don't have snapshot-aware-defrag, and in that case, the implication... and his result... remains. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman