[ceph-users] Is there an efficient way to list all namespaces in a pool?

Hello everyone, I've been wondering if there is a way of listing all namespaces in a RADOS pool in a way that is both human- and machine-readable, and is more efficient than this: rados -p <pool> ls --all -f json \ | jq -r "[.[] | .namespace] | unique" There are of course several variations of this approach, but they all seem to boil down to enumerating *all objects* and then picking out their namespaces — which is, shall we say, impractical if a pool contains millions of objects. Does a fundamentally different option exist? Cheers, Florian