Hi all, I'm missing around with "rbd layering" to store some ready-to-use templates (format 2) in a template pool : Rbd -p templates ls Ubuntu1404 Centos6 ... Rbd snap create templates/Ubuntu1404 at Ubuntu1404-snap-protected Rbd snap protect templates/Ubuntu1404 at Ubuntu1404-snap-protected Rbd clone templates/Ubuntu1404 at Ubuntu1404-snap-protected kvm1/Ubuntu1404-snap-protected-children My libvirt key is created with : Ceph auth get-or-create client.kvm1 mon 'allow r' osd 'allow class-read object_prefix rbd_children, allow rwx pool=kvm1, allow r pool=templates' But read permission for the pool 'templates' seems to be not enough, libvirt is complaining "RBD cannot access the rbd disk kvm1/Ubuntu1404-snap-protected-children" so : Ceph auth get-or-create client.kvm1 mon 'allow r' osd 'allow class-read object_prefix rbd_children, allow rwx pool=kvm1, allow rwx pool=templates' It's actually working but it's probably a bit too much, because I don't want people to be able to modify the parent template so do I have a better choice ? Libvirt seems to be happier but this clone is read-only and I want now people to use this OS image as a base file and write differences in a backing file (like with qemu ... -b ...). How can I do such a thing ? or maybe I'm doing it in a wrong way... any help ? Thanks -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20140702/cd97ab99/attachment.htm>