Ceph » rbd

From http://permalink.gmane.org/gmane.comp.file-systems.ceph.devel/15064:

For example, there could be just:

rbd_create_default_format UINT default 1

or we could add other options to adjust the rest of the image creation
parameters i.e.:

rbd_create_default_object_order INT default 22

// these only apply to format 2
rbd_create_default_features UINT64 default 1 # 1 for layering, 3 for layering+stripingv2
rbd_create_default_stripe_count UINT64 default 1 # changing requires stripingv2 feature
rbd_create_default_stripe_unit UINT64 default 4194304 # changing to non-object size requires stripingv2 feature

For backwards compatibility, the default values preserve the existing
behavior of rbd_create(), but when you run qemu-img you could change
them to create format 2 images and potentially change the striping
as well. These options could be easily backported to cuttlefish
and bobtail.