Hi I read from an article that said use preallocation can improve disk I/O performance in kvm, when I add it to openstack, suck error come to me
(nova.rpc.amqp): TRACE: Stderr: 'Backing file and preallocation cannot be used at the same time\nqemu-img: /usr/local/lib/python2.7/dist-packages/nova-2012.1-py2.7.egg/instances/instance-0000000e/disk: error while creating qcow2: Invalid argument\n' I was added it to utils.py in virt/libvirt directory (line 77) def create_cow_image(backing_file, path): """Create COW image Creates a COW image with the given backing file :param backing_file: Existing image on which to base the COW image :param path: Desired location of the COW image """ execute(FLAGS.qemu_img, 'create', '-f', 'qcow2', '-o', 'preallocation=metadata,cluster_size=2M,backing_file=%s' % backing_file, path) here is the article: http://itscblog.tamu.edu/improve-disk-io-performance-in-kvm/ so what is Backing file for, can I disable it for use preallocation cause I can't got both Thanks -- =========================== William Herry williamherrych...@gmail.com
_______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp