[pve-devel] ceph hammer : new objetmap features (fast resize, snapshot, ....)

[Alexandre DERUMIER]

Hi,

Ceph hammer has been released and have a cool new feature called object map
https://wiki.ceph.com/Planning/Blueprints/Hammer/librbd%3A_shared_flag%2C_object_map

which allow fast resize, snapshots,....  (and also async).


This require ceph hammer and librbd hammer, and require rbd volume settings:

-exclusive locking + objectmap enable. (can be done with rbd cli).


I would like to implement this, but I don't know which is the best place for this option:

-storage.cfg (rbd plugin) ?

this will enable exclusive locking globally, 
but maybe users want to share some rbd volume across multiple vms (with ocfs2 on top of rbd virtio device for example)
 

-in qemu drive options 
 This could allow to enable|disable locking by disk easily. But this is very rbd specific.



Any opinions?