From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.fusionio.com ([66.114.96.30]:52190 "EHLO mx1.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761301Ab2KAOn0 (ORCPT ); Thu, 1 Nov 2012 10:43:26 -0400 Date: Thu, 1 Nov 2012 10:43:23 -0400 From: Chris Mason To: Liu Bo CC: "linux-btrfs@vger.kernel.org" Subject: Re: [PATCH 2/2] Btrfs: make snapshot-aware defrag as a mount option Message-ID: <20121101144323.GB8307@shiny> References: <1351333721-3220-1-git-send-email-bo.li.liu@oracle.com> <1351333721-3220-2-git-send-email-bo.li.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <1351333721-3220-2-git-send-email-bo.li.liu@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Sat, Oct 27, 2012 at 04:28:41AM -0600, Liu Bo wrote: > This feature works on our crucial write endio path, so if we've got > lots of fragments to process, it will be kind of a disaster to the > performance, so I make such a change. > > One can benifit from it while mounting with '-o snap_aware_defrag'. I think we should always prefer to maintain snapshot cloning as much as possible, and have a specific option to defrag that makes it break the clone in favor of removing fragmentation. So, please keep the snapshot aware defrag the default ;) Thanks for taking these patches up again! -chris