k8s kernel clients: reasonable number of mounts per host, and limiting num client sessions

Hi, Context: one of our users is mounting 350 ceph kernel PVCs per 30GB VM and they notice "memory pressure". When planning for k8s hosts, what would be a reasonable limit on the number of ceph kernel PVCs to mount per host? If one kernel mounts the same cephfs several times (with different prefixes), we observed that this is a unique client session. But does the ceph module globally share a single copy of cluster metadata, e.g. osdmaps, or is that all duplicated per session? Can anyone estimate how much memory is consumed by each mount (assuming it is a client of an O(1k) osd ceph cluster)? Also, k8s makes it trivial for a user to mount a single PVC from hundreds or thousands of clients. Suppose we wanted to be able to limit the number of clients per PVC -- Do you think a new `max_sessions=N` cephx cap would be the best approach for this? Best Regards, Dan