Open Stack

Hi,

I'm currently evaluating our new OpenStack environment (Train),  
testing the usual scenarios. In the past I've had issues with nova and  
rbd backend, when the compute nodes used to download rbd images just  
to re-import them back to the ceph cluster instead of simply cloning  
an image.

The cause was the show_multiple_locations option that was marked  
deprecated since Pike but in fact it's still necessary. The release  
notes of Pike, Queens, Rocky and Stein all mention that the workaround  
is still required:

> The show_multiple_locations configuration option remains deprecated  
> in this release, but it has not been removed. > (It had been  
> scheduled for removal in the Pike release.) Please keep a watch on  
> the Glance release notes and the > glance-specs repository to stay  
> informed about developments on this issue.

The Train release notes don't mention this option anymore but my tests  
show that it's still required to avoid unnecessary rbd exports/imports.

Maybe the release notes for Train should be updated to cover this  
issue. In case I missed any further information that already addresses  
this I apologize.

Best regards,
Eugen