[libvirt-users] Libvirt pool cannot see or create rbd clones

[Weller, Lennart]

Hello everyone,

To increase my odds of finding an answer I also wanted to ask here.
This is my post from serverfault[1] in verbatim:

While trying to get a cloned disk running from my OS snapshot I run
into the problem that Libvirt cannot see existing images cloned from a
snapshot. Created via:

# rbd -p vmdisks clone vmdisks/coreos_2023 at base vmdisks/coreos00.disk

The base image has the one snapshot 'base' and is protected. The cloned
disk is created just fine:

# rbd -p vmdisks info coreos00.disk
rbd image 'coreos00.disk':
        size 8.49GiB in 2174 objects
        order 22 (4MiB objects)
        block_name_prefix: rbd_data.48a99c6b8b4567
        format: 2
        features: layering
        flags: 
        create_timestamp: Thu Apr 25 14:46:52 2019
        parent: vmdisks/coreos_2023 at base
        overlap: 8.49GiB

I temporarily have Libvirt configured with a rbd pool that uses the
ceph admin user. But I cannot see the cloned disk. Just the parent:

virsh # vol-list --pool rbd_image_root
 Name                 Path                                    
---------------------------------------------------------------------
---------
 coreos_2023 vmdisks/coreos_2023     

If I try to create the cloned image from within virsh I run into the
following issue:

virsh # vol-clone --pool rbd_image_root coreos_2023 coreos00.disk
error: Failed to clone vol from coreos_2023
error: failed to iterate RBD snapshot coreos_2023 at base: Operation not
permitted

Note that this pool uses the Ceph admin user which makes the Operation
not permitted a tad odd.

Am I missing a configuration option here that would allow for the pool
to use clones? I can't find any information on this in the
documentation so far. And the source code of libvirt looks like it
should support both features.

Versions:

Libvirt Machine: Ubuntu 18.04
Compiled against library: libvirt 4.0.0
Using library: libvirt 4.0.0
Using API: QEMU 4.0.0
Running hypervisor: QEMU 2.11.1

Ceph Machine: openSUSE Leap 42.3
Ceph 12.2.5


[1] 
https://serverfault.com/questions/964586/libvirt-pool-cannot-see-or-create-rbd-clones