From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.225]:31219 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751554AbaLaXi6 (ORCPT ); Wed, 31 Dec 2014 18:38:58 -0500 Message-ID: <54A48910.60701@ubuntu.com> Date: Wed, 31 Dec 2014 18:38:56 -0500 From: Phillip Susi MIME-Version: 1.0 To: ashford@whisperpc.com CC: Jose Manuel Perez Bethencourt , Chris Murphy , "sys.syphus" , Btrfs BTRFS Subject: Re: I need to P. are we almost there yet? References: <7e0d08fddb1e0060f756690f6c82c350.squirrel@webmail.wanet.net> <54A31CAE.4020606@ubuntu.com> <40b56c60ddd4801295a92c4b11d5c08e.squirrel@webmail.wanet.net> <54A3633C.3040609@ubuntu.com> <1da0cf9a75a357c960af323aa56c7530.squirrel@webmail.wanet.net> In-Reply-To: <1da0cf9a75a357c960af323aa56c7530.squirrel@webmail.wanet.net> Content-Type: text/plain; charset=windows-1252 Sender: linux-btrfs-owner@vger.kernel.org List-ID: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On 12/31/2014 12:27 PM, ashford@whisperpc.com wrote: > I see this as a CRITICAL design flaw. The reason for calling it > CRITICAL is that System Administrators have been trained for >20 > years that RAID-10 can usually handle a dual-disk failure, but the > BTRFS implementation has effectively ZERO chance of doing so. Sure, but you never *count* on that second failure since it is a ( relatively even ) probability game. > In order to remove this potentially catestrophic confusion, BTRFS > should either call their "RAID-10" implementation something else, > or they should adhere to the long-established definition of > RAID-10. Personally I'd prefer it follow the way mdadm does it, which is much better than what the rest of the industry calls raid-10, which is to say, simply a naive raid-0 on top of raid-1. I'm very happy with my 3 disk offset layout raid-10 which gets the sequential read throughput of a 3 disk raid-0, while still being able to handle a single drive failure. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBCgAGBQJUpIkQAAoJENRVrw2cjl5R/wAIAKNU0NfEFGXLQK0lB1kZMJQt WrBjKih8xG2WIYAqYCHoNTWJtmCZOCHtltt+OsUb8Pa8u075ALtEQBRNminLLuqV LjREOyOzvzaDfNSEhptdBZ4YazqFt6UChWtu7RWhMtb7u61pmqMJatDhxLe+2CF9 YQE3qgLfP+PAMIGO/xN5m+hYba4hbF/MoqQ/XN7Z1VWvT9FNR7Dn8frflpmI2Cyh iAravNS78hUjbxTtNz1qVXLosDVsjyZpz9UY9occNJ/vlF/GMd5q2c8xXkDTczGB O9B55OXGzfmzPZzlNJ2MyBLgwQx/huPH8RiyuuIdy3AVubc/pXuAZQqaydf/lQg= =qwW+ -----END PGP SIGNATURE-----