warning - backup fails when renaming or dropping a collection or index
@@ -288,6 +288,9 @@ Starting a backup
$ pbmctl run backup --description "Test backup 01" --storage=./storages.yml
+While the ``pbmctl run backup`` operation is running, neither rename nor drop
+collections or indexes from the backup lest the backup operation should fail.
+
.. _pbm.running.backup.listing:
Listing all completed backups
