Domino 12+ default native backup is a very easy to use option, which also works on Docker containers.
The resulting backup to a file target is always consistent, because delta information is always applied to the backup file.
But a file target raises the challenge that the whole NSF data will be copied to the target file-share or disk. Therefore a de-duplicating target is highly recommended.
I took a look into ZFS in detail in my new local setup to test out performance.
This is a companion discussion topic for the original entry at https://blog.nashcom.de/nashcomblog.nsf/dx/high-domino-backup-performance-with-native-zfs-storage-on-proxmox.htm