From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:60241 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1755218AbbJ1Blp convert rfc822-to-8bit (ORCPT ); Tue, 27 Oct 2015 21:41:45 -0400 From: Zhao Lei To: CC: References: <20151027142011.GT13624@twin.jikos.cz> In-Reply-To: <20151027142011.GT13624@twin.jikos.cz> Subject: RE: [PATCH] btrfs-progs: mkfs: Enable -d dup for single device Date: Wed, 28 Oct 2015 09:41:30 +0800 Message-ID: <008101d11121$c5ee0b40$51ca21c0$@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi, David Sterba > -----Original Message----- > From: David Sterba [mailto:dsterba@suse.cz] > Sent: Tuesday, October 27, 2015 10:20 PM > To: Zhao Lei > Cc: linux-btrfs@vger.kernel.org > Subject: Re: [PATCH] btrfs-progs: mkfs: Enable -d dup for single device > > On Tue, Oct 13, 2015 at 06:29:41PM +0800, Zhao Lei wrote: > > Current code don't support dup profile in single device, except it is > > in mixed mode, because following reason: > > 1: In some ssd with deduplication function, it have no effect. > > 2: For a physical device, it the entire disk broken, -d dup can > > not help. > > 3: Half performance comparing with single profile. > > 4: We have a workaround: Create multi-partition in single device, > > and btefs will treat them as multi device. > > > > Instead of refuse -d dup, we have a better choise: > > Give user a chance to select, and output a warning to notice above > > problem. > > > > Signed-off-by: Zhao Lei > > FYI, I've queued the patch for 4.4 (or later) whenever we're ready on the kernel > side. Thanks. I'm doing relative tests(xfstests, userland tools, functions as scrub, balance, ...) on it. Thanks Zhaolei