[ed25519FUUU]

I noticed that enabling compression on zfs made a huge difference with the source size of some of my largely text file petitions. I never turned on deduplication because I don’t want to bother with the memory overhead, but I bet that would help even further.

[ggm]

Most ZFS howto's now recommend against dedup on the prolongued memory cost consequences. Yes, you would get some block level compression outcome. But, you enter the cost/benefit hell of balancing CPU and memory at runtime.

[Reelin]

Can't you periodically run the dedup out of band (for example whenever you scrub)? https://btrfs.wiki.kernel.org/index.php/Deduplication

[ed25519FUUU]

I was just googling this myself and I think this is a feature that btrfs has over zfs. There’s no way to do native offline deduplication as far as I could find.