From nobody Mon Sep 16 19:14:07 2024 Delivered-To: importer2@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer2=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1675285998; cv=none; d=zohomail.com; s=zohoarc; b=mPctNP1lL9h5RyNI/OVfhcjhUPZDJ3kVCWYaL8Jcj6sTMquxTmYj5bmfAGvAPcchOCscdyBZ+poZQzG/fOA4R4Z8zXhkI6XR05PbszR7EKe4rZilwGDooIkEkpwgN9vkBg1rVUrzf1oi5N8XowZFX3N9DoEDaK1zHmmTjKB7y0M= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1675285998; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=uHWRR9w1QzyIfUJvtG7FAfTWAnsQnxANw/2ngu7uzmI=; b=XWurZxp1dSf1hbi8jM1MDZb0jKabnIIjedZXLeJm+PQK6xP3iluvcwjg5GldkycZW/GKnQTSQOGviWV9dbR2HKaFNfOnUT9QBBQ6RG2ScKMl0tNCio5sfPZ6fFGOmymvFZDKOuHQ7/5jnz7rSGzqOoWbzETAig2lP2dFLs3CGwM= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer2=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1675285998416507.56912753993583; Wed, 1 Feb 2023 13:13:18 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pNKPg-0001Lc-PX; Wed, 01 Feb 2023 16:13:04 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pNKPe-0001K8-Iy for qemu-devel@nongnu.org; Wed, 01 Feb 2023 16:13:02 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pNKPc-0003ca-Fd for qemu-devel@nongnu.org; Wed, 01 Feb 2023 16:13:02 -0500 Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-76-mn2VY8gqPGWksTp_LR4RrQ-1; Wed, 01 Feb 2023 16:12:56 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8140E3C02547; Wed, 1 Feb 2023 21:12:56 +0000 (UTC) Received: from localhost (unknown [10.39.192.164]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0C27A2166B33; Wed, 1 Feb 2023 21:12:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675285979; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uHWRR9w1QzyIfUJvtG7FAfTWAnsQnxANw/2ngu7uzmI=; b=GbjVYQVxn93AoSEJf+LMoVZGmgeej/EjdmxiZQKSMC1Z73GB0P9JBhgC+EfzGCEwD4dKjE GsdNcaIo+14DSXGescBucmslzqGxlMNLaiJLTgIX7J92j/PYObkyCdIIknqlGT3b7tJJ4j AHFSNT/D1DK0L5Zj5N/9cfUcZUw6SxU= X-MC-Unique: mn2VY8gqPGWksTp_LR4RrQ-1 From: Stefan Hajnoczi To: Cc: , Kevin Wolf , mjt@tls.msk.ru, Stefan Hajnoczi Subject: [PATCH 3/5] docs: flesh out raw format driver description Date: Wed, 1 Feb 2023 16:12:32 -0500 Message-Id: <20230201211234.301918-4-stefanha@redhat.com> In-Reply-To: <20230201211234.301918-1-stefanha@redhat.com> References: <20230201211234.301918-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer2=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer2=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer2=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1675285998815100002 Content-Type: text/plain; charset="utf-8" Modernize the description and document the size=3D/offset=3D runtime options. Signed-off-by: Stefan Hajnoczi --- docs/system/qemu-block-drivers.rst.inc | 32 ++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 5 deletions(-) diff --git a/docs/system/qemu-block-drivers.rst.inc b/docs/system/qemu-bloc= k-drivers.rst.inc index be6eec1eb6..ec9ebb2066 100644 --- a/docs/system/qemu-block-drivers.rst.inc +++ b/docs/system/qemu-block-drivers.rst.inc @@ -16,11 +16,11 @@ options that are supported for it. .. option:: raw =20 Raw disk image format. This format has the advantage of - being simple and easily exportable to all other emulators. If your - file system supports *holes* (for example in ext2 or ext3 on - Linux or NTFS on Windows), then only the written sectors will reserve - space. Use ``qemu-img info`` to know the real size used by the - image or ``ls -ls`` on Unix/Linux. + being simple and easily exportable to all other emulators. Modern + file systems support *holes* (for example in btrfs/XFS/ext4 on + Linux or NTFS on Windows) where space is allocated on demand as sectors = are + written. Use ``qemu-img info`` to know the real size used by the image or + ``ls -ls`` on Unix/Linux. =20 Supported create options: =20 @@ -33,6 +33,28 @@ options that are supported for it. for image by writing data to underlying storage. This data may or may not be zero, depending on the storage location. =20 + Supported runtime options: + + .. program:: raw + .. option:: offset + + The byte position in the underlying file where the virtual disk starts. + This is handy when you want to present just a single partition from a + physical disk as the virtual disk. This option is usually used in + conjunction with the ``size`` option. + + .. option:: size + + Limit the virtual disk size to the given number of bytes, regardless o= f how + large the underlying file is. This option is usually used in conjuncti= on + with the ``offset`` option. + + Note the raw format can be omitted when no runtime options are being use= d. In + that case the raw format does nothing besides forwarding I/O requests to= the + protocol blockdev. You can improve performance slightly by eliminating + ``--blockdev raw,file=3Dfile0,node-name=3Ddrive0`` and renaming the "fil= e0" + blockdev to "drive0". + .. program:: image-formats .. option:: qcow2 =20 --=20 2.39.1