From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wido den Hollander Subject: QCOW2 to RBD format 2 in one step Date: Tue, 14 May 2013 12:16:32 +0200 Message-ID: <51920F00.406@42on.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from websrv.42on.com ([31.25.102.167]:58995 "EHLO websrv.42on.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756451Ab3ENKQf (ORCPT ); Tue, 14 May 2013 06:16:35 -0400 Received: from [IPv6:2a00:f10:113:0:7cc5:df83:59c0:f2cf] (unknown [IPv6:2a00:f10:113:0:7cc5:df83:59c0:f2cf]) by websrv.42on.com (Postfix) with ESMTPSA id AB0A3BF650 for ; Tue, 14 May 2013 12:16:32 +0200 (CEST) Sender: ceph-devel-owner@vger.kernel.org List-ID: To: "ceph-devel@vger.kernel.org" Hi, While working on the CloudStack code for 4.2 I'm running into some problems with QCOW2 and RBD format 2. A quick cap of the problem: CloudStack stores all the templates on "Secondary Storage" as QCOW2 files. When a VM is deployed, this image will be copied (once) from Secondary Storage to Primary Storage, this is done by qemu-img which does the conversion. When the image is on Primary Storage it will be copied to the destination volume and the Instance/VM is started. In that last step I want to use layering, but the problem is that my image is RBD format 1 due to the qemu-img copy. I can skip the qemu-img copy, but I have to find a way to go from QCOW2 to RBD format 2 in preferably one step. There is a issue about this in the tracker [0], but that won't be finished on time. Another idea would be to do QCOW2 -> RAW -> RBD format 2, but that extra step will take a lot of time. It would also require some temporary storage on the hypervisor. I also thought of creating the RBD image prior to converting to it, but that fails, since qemu-img won't let you convert to a already existing image. Any brights ideas? Maybe even doing the QCOW2 -> RAW format in memory? In Java? The goal is to go from QCOW2 to RBD format 2 in one step. [0]: http://tracker.ceph.com/issues/4897 -- Wido den Hollander 42on B.V. Phone: +31 (0)20 700 9902 Skype: contact42on