This method increases the partition power of an existing ring by one.
It does not move any data nor does it exposes a CLI command yet; it is only intended to be used in a future version to do the actual ring modification itself.
If an operator stops the cluster, increases the partition power and renames & hardlinks the existing data it is possible to do a power shift without actually moving data. Please see the partition power spec for further details: http://specs.openstack.org/openstack/swift-specs/specs/in_progress/increasing_partition_power.html
Per discussion with cshwede and the Swift team, moving this to 11.
Adding needinfo on cschwede. Please discuss with zaitcev whether the following bug is a duplicate of this one: https://bugzilla.redhat.com/show_bug.cgi?id=1257300 and close the appropriate bug as a duplicate if appropriate.
Closing this bug; the described method is already included in the upstream release. BZ#1257300 is still valid, because it exposes the method to the CLI, making it usable by the operator.