Hi Kevin
Thanks for the reply - if I run MongoDB Operator (non sharding ! ← because of listDatabases) just as a replicaset, I recently created 500k databases each with 5 collection → 5M files.
It runs ok - but the problem is now, if you “shutdown” then there seems a problem with the MongoDB Operator/Replicaset - the 3rd instance shutdowns correctly, the 2nd and first seem to fail to shutdown properly which causes a “repair” then these instances are “powered on”.
So in theory it is much much better - but the stuff “around” has problems.