File system recommendation for production systems?

Hello,

Is there a Linux file system recommended by CrateDB for production deployments and workloads? E.g. XFS or ext4?

No, either of the two mentioned should be fine. Performance difference most likely relates to actual use cases.

Rather stay away from ZFS, as Lucene already compresses data anyway and caching should also rather be handled by Lucene / CrateDB.