From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [195.159.176.226] ([195.159.176.226]:49999 "EHLO blaine.gmane.org" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S932853AbcJNVUL (ORCPT ); Fri, 14 Oct 2016 17:20:11 -0400 Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1bv9tc-0000M6-Gc for linux-btrfs@vger.kernel.org; Fri, 14 Oct 2016 23:20:04 +0200 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: RAID system with adaption to changed number of disks Date: Fri, 14 Oct 2016 21:19:40 +0000 (UTC) Message-ID: References: <20161011160601.GI7683@carfax.org.uk> <3da9a459-c63b-570c-5b42-c7186b3a74fd@cn.fujitsu.com> <20161012043718.GW21290@hungrycats.org> <37578baa-556b-d3f7-45bd-10843124dea1@cn.fujitsu.com> <20161012171936.GD26140@hungrycats.org> <16a02312-a74c-6e2d-08ae-7fa479823341@cn.fujitsu.com> <20161013210346.GY21290@hungrycats.org> <20161014195544.GZ21290@hungrycats.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Zygo Blaxell posted on Fri, 14 Oct 2016 15:55:45 -0400 as excerpted: > The current btrfs raid5 implementation is a thin layer of bugs on top of > code that is still missing critical pieces. There is no mechanism to > prevent RMW-related failures combined with zero tolerance for > RMW-related failures in metadata, so I expect a btrfs filesystem using > raid5 metadata to be extremely fragile. Failure is not likely--it's > *inevitable*. Wow, that's a signature-quality quote reflecting just how dire the situation with btrfs parity-raid is ATM. First sentence for a short sig, full paragraph for a longer one. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman