From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16EA5C433F5 for ; Wed, 20 Apr 2022 02:20:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358910AbiDTCXA (ORCPT ); Tue, 19 Apr 2022 22:23:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241043AbiDTCW5 (ORCPT ); Tue, 19 Apr 2022 22:22:57 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.15.19]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6B482716C for ; Tue, 19 Apr 2022 19:20:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1650421202; bh=ugRbclLBbjosX4R4SmB/GkQlBXKTdbOXRw1LlK7ztvo=; h=X-UI-Sender-Class:Date:Subject:From:To:References:In-Reply-To; b=cOt0ROthaJnFv5ZbDIdS7E4fZNbnAYybQysdinOTtj4NPMlACW+SByzj/Dlt7SK2s iUbqCma9IXXry19VAVvvTnWhO3LIZ+ihdsE7IdKi+YYccTx0A6dRCyjjLkkYj3PmjY 7MANpfecHVxdER0IFkm290NQZsqfIhNAtFdvcj6A= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.net (mrgmx005 [212.227.17.184]) with ESMTPSA (Nemesis) id 1MmUHj-1oOp1c10Az-00iSV5; Wed, 20 Apr 2022 04:20:02 +0200 Message-ID: Date: Wed, 20 Apr 2022 10:19:58 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: RAID-[56] stabilisation Content-Language: en-US From: Qu Wenruo To: Roy Sigurd Karlsbakk , linux-btrfs References: <22677769.8507095.1650409322744.JavaMail.zimbra@karlsbakk.net> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:rwyfgSu7Kbtfk9Tg9GAwAWEL1Q9tCYpAdq3l8KlDuEWpIZhuquq lRXjOKfSEhm3AXAlNtZxalYvLx09PrpcaxW8mSQLY112sJGtsUoJ2m3kpN2AEc3bj3eu5xJ 6LXXrWi0wUN9+spkcLM1O0KdhYVdkfT8YWW8DRRPb4cupkDSEtyZfhHhL/NS+PczTPl0U/6 rdSLvMzFykoe2p0d2rHuw== X-UI-Out-Filterresults: notjunk:1;V03:K0:cWLOcuA/gkQ=:w3Pmh4IhM4xnFjaQQESpXE uADY81R6kk3jrfvAPUQUeKiSJdDRKR0bZm/WcR1EnCFkjd0ovZ0c8ywxZCZNuc022PEUWdNgg /3cTn/VqVKsuAZqEWkirFSerOr0UMrLGb7sRhrMMb9bqxCQUCxR6wZHLLfrEfsyY3LHPyB8kf VB2YvmfJLemYUPjWEUUA9xq/OAXheAhQA7OGkAViEqTvR3quBsYGugZ57BRvPB8GocPMlh1OD zvmjDiuBplunYGA6GJYrnEhRQt4mG3JEudbAtBJJekuIjS7Frw7UhnemEaIWRAsRtRAMQPhvu HtYE2FdJxyxfZzCFKexDMtyUUACETZpBM2YNzinB4788xfHkh3g90Cit3x7PjQMAk619OXhrf VNs/0EI26Y0VkFcw3VaJurL9qM6R+W10Ne/VztNL6etTD2gETbCdpv71KC4b17LIVzPbYLcap xXdJm3d2JhPBU7Aw9L4TyJA1t5U7sZ+FD09cyR4L/lrBKCFZlqUvHJ1fMyPBPu4D45fPd3ppw sayf21MGI1v4fqs7F+EquE2lOk4kpWCHNAs5sVrWrkEAimXi459xIKpK7vgzC2Xc8Qr3zarzk qpeMgd0iSDK52DfA6cGCmFiwFYtpw7mn7wwQEjLasA0XFTJ7GdfKxGTUKaqCIJsCX5Vk3hGh+ BsaOplhJ4n1gWKOh6mBI7NMJbmJZWrEN7XaeLP2ZjUuVKA/RFncWJ6QEuQCFfAUAfiT0nVcay COBb0I8YlL+38U1CUTDu8yqcSZNwT2K7OlRyuzSWkDPbnN0/8lNchmTbVglXiN/U3FMj5uD1L HhnkStmuHsDYwm0MIVGCUasPBuHiOD3Q+Ruz8B/FuCL/h5K0DxMePgWNmPEK2Ub6RWglmhOZ5 ZHQa8WK0LToB7oA/d2S9cyRrPW2ngZ4wHy8SmRp56xSfs6XZXZSbPd+dy2KFQaqc/5NTuq/gx 6+8vp48y0CqJTh0rVlKNf7fPowqSkNzOaH8TkW7VwR0anC6jjZO2ey51XzWCEz6tqmusYjN+h gF7gSdjR24BG4FP7cWAYn5zfjp9yF5j24itevpdk0cI7lTOkY3L7AuL5gFxGOHJm61NcNYjye 59JiDw4GLZA2zU= Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2022/4/20 10:17, Qu Wenruo wrote: > > > On 2022/4/20 07:02, Roy Sigurd Karlsbakk wrote: >> Hi all >> >> It's been a wee bit more than a decade since I started to look into >> btrfs as a possible ZFS replacement. I just wonder when one can expect >> RAID-[56] to stabilise as in usable for production, since this is, for >> my use, rather critial. > > Currently the main problem for btrfs RAID56 is write-hole. > > To solve it, either we need a big feature in extent allocator (to avoid > allocate extents in the partial written stripe), or go traditional > journal based RAID56 (needs a new on-disk format change, and new code). > > > If your use case can rule out power loss (by using UPS) and unexpected > shutdown (no way to prevent kernel panic though), OR you can afford a > full btrfs scrub before any write (can be very time consuming), I mean "before any write after an unexpected shutdown/crash" If you can ensure your fs is shutdown cleanly, then no problem at all. > you can > try btrfs RAID56. > > There is some plan to implement a RAID56 journal, but there is no > concrete time table for that yet. > > > Or, you can run single device btrfs on md/dm-raid56. > > Thanks, > Qu > >> >> Vennlig hilsen / Best regards >> >> roy >> -- >> Roy Sigurd Karlsbakk >> (+47) 98013356 >> http://blogg.karlsbakk.net/ >> GPG Public key: http://karlsbakk.net/roysigurdkarlsbakk.pubkey.txt >> -- >> I all pedagogikk er det essensielt at pensum presenteres >> intelligibelt. Det er et element=C3=A6rt imperativ for alle pedagoger = =C3=A5 >> unng=C3=A5 eksessiv anvendelse av idiomer med xenotyp etymologi. I de >> fleste tilfeller eksisterer adekvate og relevante synonymer p=C3=A5 nor= sk.