[ceph-users] Unable to enable RBD-Mirror Snapshot on image when VM is using RBD

This is a odd one. I don't hit it all the time so I don't think its expected behavior. Sometimes I have no issues enabling rbd-mirror snapshot mode on a rbd when its in use by a KVM VM. Other times I hit the following error, the only way I can get around it is to power down the KVM VM. root@Ccscephtest1:~# rbd mirror image enable CephTestPool1/vm-101-disk-0 snapshot 2021-01-29T09:29:07.875-0500 7f1e99ffb700 -1 librbd::mirror::snapshot::CreatePrimaryRequest: 0x7f1e7c012440 handle_create_snapshot: failed to create mirror snapshot: (22) Invalid argument 2021-01-29T09:29:07.875-0500 7f1e99ffb700 -1 librbd::mirror::EnableRequest: 0x5597667fd200 handle_create_primary_snapshot: failed to create initial primary snapshot: (22) Invalid argument 2021-01-29T09:29:07.875-0500 7f1ea559f3c0 -1 librbd::api::Mirror: image_enable: cannot enable mirroring: (22) Invalid argument