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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CD69C4332B for ; Sat, 21 Mar 2020 05:42:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 69EE620739 for ; Sat, 21 Mar 2020 05:42:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UkO+GeN7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727199AbgCUFkz (ORCPT ); Sat, 21 Mar 2020 01:40:55 -0400 Received: from mail-lf1-f45.google.com ([209.85.167.45]:34698 "EHLO mail-lf1-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725763AbgCUFky (ORCPT ); Sat, 21 Mar 2020 01:40:54 -0400 Received: by mail-lf1-f45.google.com with SMTP id i1so5490610lfo.1 for ; Fri, 20 Mar 2020 22:40:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=/BWYav3tVjustkq9d3DEhnzRYo92RlCeY2F9zrABggA=; b=UkO+GeN7ZB5guE4uD9nrAUkvKrfySUUVDhGRai/II9AOKp2nZ0E8gs4r9RURwkWPOU fjFPjBjore63ix2nKPvBPVbmt4s9zXF4SPWcYe5RhnADNlVBKeFWgU0UuIsr0KvOisg0 Wog2l7rcUSy5YXmTmL7aL3vot3vhCdnfbw85nfGXNk6npcTZ5WrCAnEt1D+U5poblx8D UlFR/YCzFqmdHXyz8yZpuLQtX0rSzWd0fjrEibKS9d4U3oew0dU1dBgMCEgArB3KSKoM /MIyUckyNi4PdDbtzZZ4H1yuODfbiN/uU263RGRNCnjuzgEtWJnjxA4u9WHDB5onV/6X yz8w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=/BWYav3tVjustkq9d3DEhnzRYo92RlCeY2F9zrABggA=; b=oo+XfrCejB8+uhjsT5PjbA3GUZdXQk5yR4ojc98JkEYL2S2ldmuZWavduTBfzJPLig lGFHoPQPT5KaOHHJ3BIan9BQ5qgzJsP6MbCpTcy43i/GRRlXxGJj+Bn82zWX0Uups9om M2RLN0a0fhUwU6DhtRr5FWnTFr7NvuFIh0HkDCxgiAPz1cHLV+Q42kbT0B2NOeSCzSsY dA6kMO9CV0J9dmutiFxZ2zDxLTyUaBuIMfDgYP4Llap0mfRGo225+y15jFClPjhp8mXp CkABnXnCXu1iM3Mp1ifqhSYjUJ93yiFxkN39CZie4f7vlGPVrimVLHxc4RsqgRicBMFO Cofg== X-Gm-Message-State: ANhLgQ3gfiKgd59H41SuW+zialayEZ7uw/0XgHmxL1hoKSkZbYPCU/RJ xrdxWMmBOgJfdOAgAPO+oX1HeKC/ X-Google-Smtp-Source: ADFU+vumOxq56FVNjO91R6/UfC3jF+wnbMCBBVO8Tw6s/4VqTxvhCW7wrrolMPqAcuKdWGHxo9ivoQ== X-Received: by 2002:a19:84c7:: with SMTP id g190mr236910lfd.204.1584769252653; Fri, 20 Mar 2020 22:40:52 -0700 (PDT) Received: from ?IPv6:2a00:1370:812d:e281:7ca7:8ec9:2456:f2b7? ([2a00:1370:812d:e281:7ca7:8ec9:2456:f2b7]) by smtp.gmail.com with ESMTPSA id x16sm4539243lji.37.2020.03.20.22.40.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 20 Mar 2020 22:40:51 -0700 (PDT) Subject: Re: Question: how understand the raid profile of a btrfs filesystem To: Zygo Blaxell , kreijack@inwind.it Cc: linux-btrfs References: <517dac49-5f57-2754-2134-92d716e50064@alice.it> <20200321032911.GR13306@hungrycats.org> From: Andrei Borzenkov Autocrypt: addr=arvidjaar@gmail.com; prefer-encrypt=mutual; keydata= xsDiBDxiRwwRBAC3CN9wdwpVEqUGmSoqF8tWVIT4P/bLCSZLkinSZ2drsblKpdG7x+guxwts +LgI8qjf/q5Lah1TwOqzDvjHYJ1wbBauxZ03nDzSLUhD4Ms1IsqlIwyTLumQs4vcQdvLxjFs G70aDglgUSBogtaIEsiYZXl4X0j3L9fVstuz4/wXtwCg1cN/yv/eBC0tkcM1nsJXQrC5Ay8D /1aA5qPticLBpmEBxqkf0EMHuzyrFlqVw1tUjZ+Ep2LMlem8malPvfdZKEZ71W1a/XbRn8FE SOp0tUa5GwdoDXgEp1CJUn+WLurR0KPDf01E4j/PHHAoABgrqcOTcIVoNpv2gNiBySVsNGzF XTeY/Yd6vQclkqjBYONGN3r9R8bWA/0Y1j4XK61qjowRk3Iy8sBggM3PmmNRUJYgroerpcAr 2byz6wTsb3U7OzUZ1Llgisk5Qum0RN77m3I37FXlIhCmSEY7KZVzGNW3blugLHcfw/HuCB7R 1w5qiLWKK6eCQHL+BZwiU8hX3dtTq9d7WhRW5nsVPEaPqudQfMSi/Ux1kc0mQW5kcmVpIEJv cnplbmtvdiA8YXJ2aWRqYWFyQGdtYWlsLmNvbT7CZQQTEQIAJQIbAwYLCQgHAwIGFQgCCQoL BBYCAwECHgECF4AFAliWAiQCGQEACgkQR6LMutpd94wFGwCeNuQnMDxve/Fo3EvYIkAOn+zE 21cAnRCQTXd1hTgcRHfpArEd/Rcb5+SczsBNBDxiRyQQBACQtME33UHfFOCApLki4kLFrIw1 5A5asua10jm5It+hxzI9jDR9/bNEKDTKSciHnM7aRUggLwTt+6CXkMy8an+tVqGL/MvDc4/R KKlZxj39xP7wVXdt8y1ciY4ZqqZf3tmmSN9DlLcZJIOT82DaJZuvr7UJ7rLzBFbAUh4yRKaN nwADBwQAjNvMr/KBcGsV/UvxZSm/mdpvUPtcw9qmbxCrqFQoB6TmoZ7F6wp/rL3TkQ5UElPR gsG12+Dk9GgRhnnxTHCFgN1qTiZNX4YIFpNrd0au3W/Xko79L0c4/49ten5OrFI/psx53fhY vLYfkJnc62h8hiNeM6kqYa/x0BEddu92ZG7CRgQYEQIABgUCPGJHJAAKCRBHosy62l33jMhd AJ48P7WDvKLQQ5MKnn2D/TI337uA/gCgn5mnvm4SBctbhaSBgckRmgSxfwQ= Message-ID: Date: Sat, 21 Mar 2020 08:40:50 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200321032911.GR13306@hungrycats.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org 21.03.2020 06:29, Zygo Blaxell пишет: > On Fri, Mar 20, 2020 at 06:56:38PM +0100, Goffredo Baroncelli wrote: >> Hi all, >> >> for a btrfs filesystem, how an user can understand which is the {data,mmetadata,system} [raid] profile in use ? E.g. the next chunk which profile will have ? > > It's the profile used by the highest-numbered block group for the > allocation type (one for data, one for metadata/system). Is "highest-numbered" block group always the last one created? Can block group numbers wrap around? Recently someone reported that after conversion block groups with old profile remained and this probably explains it - conversion races with new allocation. >> So the question is: the next chunk which profile will have ? >> Is there any way to understand what will happens ? Well, from that explanation it is not possible using standard tools - one needs to crawl btrfs internals to find out the "last" block group.