Re: [PATCH v4 0/4] qemu: Support rbd namespace attribute

On Mon, Aug 24, 2020 at 11:09 PM Jason Dillaman <jdillama(a)redhat.com&gt; wrote: <pool-name> ? I am confused here. Do you mean the pool-namespace? I think the only separated namespace is sensible here. Because there are 3 ways to express the rbd image path with namespace: 1. <pool>/<namespace>/<image> e.g: the rbd info comand and the qemu-img comand with legacy rbd path: ➜ ~ rbd -c ~/.ceph/ceph.conf -k ~/.ceph/ceph.client.admin.keyring info rbd/hhan/1 rbd image '1': size 100 MiB in 25 objects ... ➜ ~ qemu-img info rbd:rbd/hhan/1:conf=/home/hhan/.ceph/ceph.conf:id=admin:key=XXXXXXX image: json:{"driver": "raw", "file": {"pool": "rbd", "image": "1", "conf": "/home/hhan/.ceph/ceph.conf", "driver": "rbd", "user": "admin"}} file format: raw ... Note that the missing namespace attribute in image json is caused by https://bugzilla.redhat.com/show_bug.cgi?id=1821528 2. only separated namespace: <pool>/><image> and namespace attribute or option e.g: the rbd command with namespace option ➜ ~ rbd -c ~/.ceph/ceph.conf -k ~/.ceph/ceph.client.admin.keyring info rbd/1 --namespace hhan rbd image '1': size 100 MiB in 25 objects order 22 (4 MiB objects) ... 3. separated pool, namespace, image e.g: qemu blockdev options of rbd: https://github.com/qemu/qemu/blob/30aa19446d82358a30eac3b556b4d6641e00b7c... ➜ ~ qemu-img info 'json:{"driver": "raw", "file": {"pool": "rbd", "image": "1", "conf": "/home/hhan/.ceph/ceph.conf", "driver": "rbd", "user": "admin", "namespace":"hhan"}}' image: json:{"driver": "raw", "file": {"pool": "rbd", "image": "1", "conf": "/home/hhan/.ceph/ceph.conf", "driver": "rbd", "user": "admin"}} file format: raw ... libvirt XML. I reject the 1st pattern because of compat issues. Suppose the 1st pattern is used, it will cause problems in the following case. Since rbd allows the image name contains '/' ➜ ~ rbd -c ~/.ceph/ceph.conf -k ~/.ceph/ceph.client.admin.keyring -p rbd ls attach-new copy hhan/2 If I used 'hhan/2' image in libvirt XML at the previous libvirt and then I updated libvirt to the version support 1st pattern, the new libvirt parse the name='rbd/hhan/2' as pool 'rbd', namespace 'hhan', image '2',instead of the pool 'rbd', image 'hhan/2', default namespace. For the 3rd pattern, separating all the attributes, the xml will look like <source protocol="rbd" pool="POOL" image="IMG" namespace="NS"> However it cannot replace the old attribute name='<pool>/<image>' because of the compatibility. What about keeping the old attribute the adapting this new pattern? Well, it looks weird only rbd protocol adapts this new pattern because all the network protocols in libvirt use the old xml pattern <source protocol="PROTO" name="XX"> (seeing the examples in https://libvirt.org/formatdomain.html#hard-drives-floppy-disks-cdroms) How about adapting this new pattern to all the network protocols? Considering the effort and the benifits of that, I think it is not worthwhile. drop the "pool_namespace" attribute" and parse the image name just The above is why I changed my mind and decided to use the only separated attribute namespace. -- Best regards, ----------------------------------- Han Han Senior Quality Engineer Redhat. Email: hhan(a)redhat.com Phone: +861065339333