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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 9D94DC35247 for ; Mon, 3 Feb 2020 19:02:03 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 6CFAC2051A for ; Mon, 3 Feb 2020 19:02:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Ck+eEPOK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6CFAC2051A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:46164 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iygyw-0006r6-IH for qemu-devel@archiver.kernel.org; Mon, 03 Feb 2020 14:02:02 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:59239) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iygxI-0006EZ-Th for qemu-devel@nongnu.org; Mon, 03 Feb 2020 14:00:23 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iygxH-0000hD-Pw for qemu-devel@nongnu.org; Mon, 03 Feb 2020 14:00:20 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:52320 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iygxH-0000gS-K0 for qemu-devel@nongnu.org; Mon, 03 Feb 2020 14:00:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580756419; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Wrl4NLlsQ1GXO/oE7WniDAQ6b1MZ9eSk9C5NfrHRMew=; b=Ck+eEPOKW1EW5xhh1jsml7hhH5MdDhQgO0JdlQ8AXZKm/4VoqBQNtuax/rtlVIXpx6j9/e WcJ5Pirfufwvs6KwVHu7Qf5CB5Sh27ULYtcUWorLXdfzjPNetv0XgXZ0vMNXOnYemwb8Gr ePOCSkFKOo59QYU0Bmf9JutUzhcAU60= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-269-hvd8QlS9O0OwVkFWObJZzg-1; Mon, 03 Feb 2020 14:00:07 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BA0F8107ACC9; Mon, 3 Feb 2020 19:00:06 +0000 (UTC) Received: from [10.3.116.181] (ovpn-116-181.phx2.redhat.com [10.3.116.181]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1750489A82; Mon, 3 Feb 2020 19:00:05 +0000 (UTC) Subject: Re: [PATCH v2 1/2] qemu-img: Add --target-is-zero to convert To: Vladimir Sementsov-Ogievskiy , David Edmondson , qemu-devel@nongnu.org, qemu-block@nongnu.org References: <20200124103458.1525982-1-david.edmondson@oracle.com> <20200124103458.1525982-2-david.edmondson@oracle.com> <4b23f9d9-efe4-000d-0d68-66028ad3d2f3@virtuozzo.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <2e7777b6-5ae0-973c-1040-dae6def3925c@redhat.com> Date: Mon, 3 Feb 2020 13:00:05 -0600 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: <4b23f9d9-efe4-000d-0d68-66028ad3d2f3@virtuozzo.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: hvd8QlS9O0OwVkFWObJZzg-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 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" On 2/3/20 12:20 PM, Vladimir Sementsov-Ogievskiy wrote: > 24.01.2020 13:34, David Edmondson wrote: >> In many cases the target of a convert operation is a newly provisioned >> target that the user knows is blank (filled with zeroes). In this >> situation there is no requirement for qemu-img to wastefully zero out >> the entire device. >> >> Add a new option, --target-is-zero, allowing the user to indicate that >> an existing target device is already zero filled. > > Hi! qemu-img.c part looks OK for me, but other doesn't apply on master now. Correct. Patch 2/2 is now obsolete and no longer necessary, and patch 1 needs some tweaks now that we don't have qemu-img.texi. > > I like this thing, and I'd like to make similar option for backup job. My followup patches to add an all-zero bit to qcow2 are also useful in this regard. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org