From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from tartarus.angband.pl ([89.206.35.136]:59034 "EHLO tartarus.angband.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753308AbcLIIoG (ORCPT ); Fri, 9 Dec 2016 03:44:06 -0500 Date: Fri, 9 Dec 2016 09:43:52 +0100 From: Adam Borowski To: Jeff Mahoney Cc: Christoph Anton Mitterer , linux-btrfs@vger.kernel.org Subject: Re: out-of-band dedup status? Message-ID: <20161209084352.GB28652@angband.pl> References: <1481222198.6563.3.camel@scientia.net> <539d7c1c-5041-fb99-0ec5-81291f9f6609@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <539d7c1c-5041-fb99-0ec5-81291f9f6609@suse.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Thu, Dec 08, 2016 at 03:15:38PM -0500, Jeff Mahoney wrote: > On 12/8/16 1:36 PM, Christoph Anton Mitterer wrote: > > I just wondered whether out-of-band/"offline" dedup is safe for general > > use... https://btrfs.wiki.kernel.org/index.php/Status kinda implies so > > (it tells about unspecified performance issues), but this seems again > > already outdated (kernel 4.7)... > > SUSE supports it in SLE12 using our 3.12 and 4.4 -based kernels. There > haven't been a lot of changes to the kernel component of it. It's > pretty simple: check to see if the ranges are identical between two > files and then reflink between them. > > > Any other things in terms of possible issues, data corruption, etc. > > that one should know when using deduplication? > > There shouldn't be. We haven't had any bug reports at SUSE. I use it on busy machines on ancient kernels (3.14, one 3.13) without any hint of problems other than dedupe itself being slow. Meow! -- u-boot problems can be solved with the help of your old SCSI manuals, the parts that deal with goat termination. You need a black-handled knife, and an appropriate set of candles (number and color matters). Or was it a silver-handled knife? Crap, need to look that up.