I have a Butterfly Backup server. I implemented a solution as described in this article: dev.to. In my sever list, I have two NAS, used as user file repositories; the files change and are changed every minute. For this reason, I have chosen to implement my backup server with an incremental engine. This is the command that starts at night:
bb backup -L /mnt/srv_user/srv.list -d /backup/srv_user -C /nas -t Unix -u unas -r 15 -e
I also followed the documentation (docs) to produce the above command, and everything seemed to be functional and properly configured. But I realized that some subfolders of the nas under backup, are transferred even if there are no changes, instead, it should create a hard link to the existing file.
This problem does not do it on all folders but only on some.