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 6600EC7EE2A for ; Sun, 4 Jun 2023 19:06:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231167AbjFDTGy (ORCPT ); Sun, 4 Jun 2023 15:06:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231389AbjFDTGx (ORCPT ); Sun, 4 Jun 2023 15:06:53 -0400 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5217D2 for ; Sun, 4 Jun 2023 12:06:48 -0700 (PDT) Received: by mail-pf1-x42a.google.com with SMTP id d2e1a72fcca58-65314ee05c6so1491480b3a.1 for ; Sun, 04 Jun 2023 12:06:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1685905608; x=1688497608; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=iKFRG4sLddr5jyH4jgTyfJ4yjF3tqwuDIQl2XFzUyrU=; b=oTCYkiFJvjVU0WBkJFOJvDisxaMyUDu3UoyebWveo08qPmVtDtkGfI1kXo4hONesQC IHAAllpJsMZq2/6OBOs+CTH3nArhy1fq2sZRoLNmnK0/O5mQpmjxQ9b0Q8d2fQp0lS33 t2p/VvHC7kKk/alw/COviCugI8S6oT4k2eO7vApYOgGX2ew2vIebB+XMuZ/OGsP+bTlX f7AgC0iBZJ3/4NA3ElZ+RtYa0STerMw+O//AWdm+Pb/vRLjuho9JIfOmgEo3cnoNnOeT 4C03ntM7QThZRfBJZv0Hf3Aqrceji1lYcAi0cJmZfhP4FVSx7nPlg7QZTwoxhAojLyHY FBdw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685905608; x=1688497608; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=iKFRG4sLddr5jyH4jgTyfJ4yjF3tqwuDIQl2XFzUyrU=; b=MYDV7zS0l81jAtwzPWTBNeqoKeBhuRgaw+PVTfYsh4dasl8ii4lxQWFSCOhNRZfHjL kMg/aQBWuYDRKEnNsUpmkHVt9NiWmOt/f2SQpKZ9+vh7xhGQknDZ0ZAsl2EvUFQWpiy9 Bz3k8VUuV7/O0uyOJWo7DtkOk7CHRO4lD1NVvmn4nutxC5lhrfR1C4m1MIqqGx96Jpt/ R6Y0aJndqoWBDYeERiMHADPR5m2xMbUKSR5Wta7xx98Msnmu+NHRYGeYGIGoP1g4nNQ1 apoHvD3Kq25bs3pZWz1ju0Nd641q/H5gnKU6AYeXgX8rpNLcH55Epl/EjNhDU+72QK9V CXfw== X-Gm-Message-State: AC+VfDzVp6hk9NNtoBd+7SGyMHHZlDXObF0Eqbm0YmaAG1xxWyBF5Dl4 Yrh5fPtxrhxmDx/rccGp8Lk= X-Google-Smtp-Source: ACHHUZ7cDgIjV0oILt0pZVD+r4aDxwUFJD0QMvse+QGJquJ/eroO8Pk1b3XFDfgRAeWKntRV/xdXLA== X-Received: by 2002:a05:6a20:1450:b0:110:9b0b:71ab with SMTP id a16-20020a056a20145000b001109b0b71abmr2574568pzi.40.1685905607854; Sun, 04 Jun 2023 12:06:47 -0700 (PDT) Received: from localhost.localdomain ([76.132.108.20]) by smtp.gmail.com with ESMTPSA id m8-20020a170902db0800b001a6ed2d0ef8sm4979072plx.273.2023.06.04.12.06.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 04 Jun 2023 12:06:47 -0700 (PDT) From: Russell Harmon To: bagasdotme@gmail.com Cc: mpatocka@redhat.com, snitzer@redhat.com, dm-devel@redhat.com, linux-doc@vger.kernel.org, Russell Harmon Subject: [PATCH v3 4/4] Document an example of how the tunables relate in dm-integrity. Date: Sun, 4 Jun 2023 12:06:04 -0700 Message-Id: <20230604190604.4800-5-eatnumber1@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230604190604.4800-1-eatnumber1@gmail.com> References: <20230604190604.4800-1-eatnumber1@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org For example, on a device using the default interleave_sectors of 32768, a block_size of 512, and an internal_hash of crc32c with a tag size of 4 bytes, it will take 128 KiB of tags to track a full data area, requiring 256 sectors of metadata per data area. With the default buffer_sectors of 128, that means there will be 2 buffers per metadata area, or 2 buffers per 16 MiB of data. Signed-off-by: Russell Harmon --- Documentation/admin-guide/device-mapper/dm-integrity.rst | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/admin-guide/device-mapper/dm-integrity.rst b/Documentation/admin-guide/device-mapper/dm-integrity.rst index 0241457c0027..d8a5f14d0e3c 100644 --- a/Documentation/admin-guide/device-mapper/dm-integrity.rst +++ b/Documentation/admin-guide/device-mapper/dm-integrity.rst @@ -213,6 +213,12 @@ table and swap the tables with suspend and resume). The other arguments should not be changed when reloading the target because the layout of disk data depend on them and the reloaded target would be non-functional. +For example, on a device using the default interleave_sectors of 32768, a +block_size of 512, and an internal_hash of crc32c with a tag size of 4 +bytes, it will take 128 KiB of tags to track a full data area, requiring +256 sectors of metadata per data area. With the default buffer_sectors of +128, that means there will be 2 buffers per metadata area, or 2 buffers +per 16 MiB of data. Status line: -- 2.34.1