Debian is a great classical Linux distro which has in turn given birth to many successful forks. We have noticed that some default installtions of current Debian versions as of 2022 do activate by default the iNOTIFY service. This seems to somehow affect (c)XSIBackup server and produces ENOSPC system call errors when the limit at /proc/sys/fs/inotify/max_user_watches is reached.
(c)XSIBackup backup repositories consist in millions of data chunks. If you enable some system such as inotify in your backup server, you will be adding some overhead to the FS and on top of that you will be bound by the limits of the iNOTIFY service itself.
It is a must to disable inotify in your host. If you don't know what it is or you don't want to go through the hassle of learning about it, then you should stick to the recommended distros: CentOS 7 and Rocky Linux 8
The only scenario in which inotify would be useful is if you are willing to create some sort of distributed backup repository system that keeps a copy of your backup repository in the cloud and you will be using iNOTIFY to move the new block files when they are detected in the repository directory structure.