On Tue, May 14, 2013 at 01:52:28PM +0200, Wido den Hollander wrote: > On 05/14/2013 12:34 PM, Leen Besselink wrote: > >On Tue, May 14, 2013 at 12:16:32PM +0200, Wido den Hollander wrote: > >>Hi, > >> > > Hi Leen, > > > > >Hi Wido, > > > >>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? > >> > > > >I'm no expert, but would it be possible to change qemu-img to support writing RAW to standard out ? > > > > No, qemu-img can't write to stdout. Due to various formats it supports. > I meant extending qemu-img to support that, it would probably be less work than the work needed for the issue below. But the longer I think about it. It would only be able to do that for RAW. And RAW isn't very efficient anyway. > >So you can run qemu-img convert and pipe that drectly to the rbd import command ? > > > > If qemu-img would support writing to stdout there is the problem > that I'm not using the rbd tool, but Java bindings for librbd and > librados. I'm trying to avoid executing from Java. > > >rbd import already supports standard in I believe. > > > >Then you don't need any temporary storage. > > > >Maybe something more efficient than RAW is possible as well ? > > > >>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 > >>-- > >>To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > >>the body of a message to majordomo@xxxxxxxxxxxxxxx > >>More majordomo info at http://vger.kernel.org/majordomo-info.html > >-- > >To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > >the body of a message to majordomo@xxxxxxxxxxxxxxx > >More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > -- > Wido den Hollander > 42on B.V. > > Phone: +31 (0)20 700 9902 > Skype: contact42on -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
