Is there any way to check that all clients are effectively using the new, secure, global_id?
Yes, once the client warning is gone.
The case from altinea seems a bit odd, but it's really the single one we currently know of behaving in an unexpected, but not confirmed wrong way. Actually it's not clear if the newer libraries are not loaded there, dynamical libraries, but I'll try to find some time to investigate this further and try to run the updates a few times, maybe I can reproduce it and update any recomendations we have here.
That said, for our various test updates and also our internal production cluster all went fine when following the recommendations described in my original first post in this thread and if you live-migrate the VMs to an upgraded host you're def. on the safe side, Altinea just asked if that could be avoided in his case, as it seemed that all VMs already use the new auth.
Followed the steps, including fully rebooting every Proxmox server and fully rebooting or live migrating every VM. Everything seems fine, besides a "pools have too many placement groups" that I already expected, but would like to be sure that all global_id are good instead of waiting 72h for them to expire and maybe cause some trouble.
That sounds good, you could check a VM process to see if they loaded an outdated librbd, use
qm list
to get the PID and run
lsof -n -p PID| grep DEL| grep rbd
, it should return nothing, which means the process loaded the rbd library currently installed on the system through the latest upgrade.
The ceph warning is actually the better check, but this ensures you're not in such an odd situation like the other user.