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Re: Lost copy-on-write feature when create volume from image with using Ceph RBD


On 04/11/2013 11:08 PM, 陈雷 wrote:
Hi, Guys

Recently I'm testing the new version of OpenStack Grizzly. I'm using Ceph
RBD as the backend storage both for Glance and Cinder.

In the old version of Folsom, when set the parameter
‘show_image_direct_url=True’ in the config file glance-api.conf, the
process of  create volume from image will be done immediately, because it
  just to create a snapshot from Ceph's image pool to volumes pool.

But now I found the feature is lost, it always perform a convert process
which will download the the whole image file from Ceph's pool of 'images'
and convert it to RAW format then upload to Ceph's pool of 'volumes' no
matter what the original format of image file is. This process take longer
time than the older version of 'Folsom'.

So is this a bug or I miss-configured something?

I'd say it's a regression that the default behavior changed, but
if you set glance_api_version=2 in your cinder.conf and restart
cinder-volume it will work.