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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 56A88CA0FE1 for ; Fri, 1 Sep 2023 10:29:06 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qc1OI-0000SU-SR; Fri, 01 Sep 2023 06:28:40 -0400 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 1qc1OC-0000Rq-WE for qemu-devel@nongnu.org; Fri, 01 Sep 2023 06:28:33 -0400 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 1qc1OA-0005gg-K5 for qemu-devel@nongnu.org; Fri, 01 Sep 2023 06:28:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1693564109; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=sJ6k8sc3WQNaZFxBVTfduaT9stgucg0qTFXYj2eSTok=; b=hhXvwEvbq0qxaSecvTCboxTPXTWDG4mgAYJWJD5Hlx2MPMjopixdJTrAR+P5O7s2Ak/eWC nUxOce0GFgHorsTl53NL/bS/mFw6JqObTTDo6TA2VGM8M9nAln2kHw3RDNaU3ZR5mRY5lL 5NQoKZAmwqtDaggGAMS+/jPyPi2RcWo= Received: from mimecast-mx02.redhat.com (mx-ext.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-484-eRSwTPnzMG6cigL187v-6w-1; Fri, 01 Sep 2023 06:28:26 -0400 X-MC-Unique: eRSwTPnzMG6cigL187v-6w-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 54D433C1ACD5; Fri, 1 Sep 2023 10:28:26 +0000 (UTC) Received: from localhost (unknown [10.42.28.187]) by smtp.corp.redhat.com (Postfix) with ESMTP id 233B11402C01; Fri, 1 Sep 2023 10:28:26 +0000 (UTC) Date: Fri, 1 Sep 2023 11:28:25 +0100 From: "Richard W.M. Jones" To: Kevin Wolf Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org Subject: Re: [PATCH] qemu-img: Update documentation for compressed images Message-ID: <20230901102825.GF7636@redhat.com> References: <20230901102430.23856-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230901102430.23856-1-kwolf@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Received-SPF: pass client-ip=170.10.133.124; envelope-from=rjones@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_H4=0.001, RCVD_IN_MSPIKE_WL=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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Sep 01, 2023 at 12:24:30PM +0200, Kevin Wolf wrote: > Document the 'compression_type' option for qcow2, and mention that > streamOptimized vmdk supports compression, too. > > Reported-by: Richard W.M. Jones > Signed-off-by: Kevin Wolf Looks good, so: Reviewed-by: Richard W.M. Jones > --- > docs/tools/qemu-img.rst | 19 +++++++++++++++++-- > 1 file changed, 17 insertions(+), 2 deletions(-) > > diff --git a/docs/tools/qemu-img.rst b/docs/tools/qemu-img.rst > index 15aeddc6d8..ca5a2773cf 100644 > --- a/docs/tools/qemu-img.rst > +++ b/docs/tools/qemu-img.rst > @@ -106,7 +106,11 @@ by the used format or see the format descriptions below for details. > > .. option:: -c > > - Indicates that target image must be compressed (qcow format only). > + Indicates that target image must be compressed (qcow/qcow2 and vmdk with > + streamOptimized subformat only). > + > + For qcow2, the compression algorithm can be specified with the ``-o > + compression_type=...`` option (see below). > > .. option:: -h > > @@ -776,7 +780,7 @@ Supported image file formats: > > QEMU image format, the most versatile format. Use it to have smaller > images (useful if your filesystem does not supports holes, for example > - on Windows), optional AES encryption, zlib based compression and > + on Windows), optional AES encryption, zlib or zstd based compression and > support of multiple VM snapshots. > > Supported options: > @@ -794,6 +798,17 @@ Supported image file formats: > ``backing_fmt`` > Image format of the base image > > + ``compression_type`` > + This option configures which compression algorithm will be used for > + compressed clusters on the image. Note that setting this option doesn't yet > + cause the image to actually receive compressed writes. It is most commonly > + used with the ``-c`` option of ``qemu-img convert``, but can also be used > + with the ``compress`` filter driver or backup block jobs with compression > + enabled. > + > + Valid values are ``zlib`` and ``zstd``. For images that use > + ``compat=0.10``, only ``zlib`` compression is available. > + > ``encryption`` > If this option is set to ``on``, the image is encrypted with > 128-bit AES-CBC. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org