On Wed, Aug 26, 2020 at 10:32:04 -0500, Eric Blake wrote:
On 8/26/20 9:56 AM, Peter Krempa wrote:
Cluster size may have performatnce implications. Propagate the cluster size used by the original image to any copy or overlay.
Peter Krempa (3): qemu: monitor: Detect image cluster size from 'query-named-block-nodes' qemu: block: Allow specifying cluster size when using 'blockdev-create' qemuBlockStorageSourceCreateDetectSize: Propagate cluster size for 'qcow2'
It's not as flexible as allowing the user to customize sizes, but it definitely makes sense and is a sane heuristic, better than adccidentally creating an overlay with 64k clusters atop a base image with 1M clusters.
Actually, I'll modify the condition in patch 3 to also check that the configured cluster size in the new image is 0 before applying one from the template image. That way it will be simpler to wire up configurable cluster size by just dealing with the XML.
Series: Reviewed-by: Eric Blake <eblake@redhat.com>
Thanks I'll push it soon.