From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from magic.merlins.org ([209.81.13.136]:42069 "EHLO mail1.merlins.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750921AbaCYB3R (ORCPT ); Mon, 24 Mar 2014 21:29:17 -0400 Date: Mon, 24 Mar 2014 18:29:16 -0700 From: Marc MERLIN To: Martin Cc: linux-btrfs@vger.kernel.org Subject: Re: Btrfs and raid5 status with kernel 3.14, documentation, and howto Message-ID: <20140325012916.GF11533@merlins.org> References: <20140323225657.GA17039@merlins.org> <20140324215239.GC11533@merlins.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Tue, Mar 25, 2014 at 01:11:43AM +0000, Martin wrote: > Yes, looking good, but for my usage I need the option to run ok with a > failed drive. So, that's one to keep a development eye on for continued > progress... So it does run with a failed drive, it'll just fill the logs with write errors, but continue working ok. > There's a big thread a short while ago about using parity across > n-devices where the parity is spread such that you can have 1, 2, and up > to 6 redundant devices. Well beyond just raid5 and raid6: > > http://lwn.net/Articles/579034/ Aah, ok. I didn't understand you meant that. I know nothing about that, but to be honest, raid6 feels like it's enough for me :) > btrfs raid1 at present is always just the two copies of data spread > across whatever number of disks you have. A more flexible arrangement is > to be able to set to have say 3 copies of data and use say 4 disks. > There's a new naming scheme proposed somewhere that enumerates all the > permutations possible for numbers of devices, copies and parity that > btrfs can support. For me, that is a 'killer' feature beyond what can be > done with md-raid for example. Right. That's on the roadmap from what I read here, just not ready yet. Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/