So I am going to setup one or more volumes on 40-60 4TB-8TB SSDs (unfortunately without PLP but high speed is not a requirement). For "reasons" I would use a filesystem type with built-in compression and in practice that means Btrfs or ZFS: cacheFS is a bit immature still and compression in F2FS (which is otherwise a very good choice in most cases whether for HDD or SSD) is a bit weird. I have used bothb extensively and I would use both on a single SSD, so no use of their built-in volume manager. The question is which one works better with GlusterFS and I guess a significant aspect is how big the GlusterFS extended attributes are "typically" and whether that much can be inlined in an i-node. ZFS inodes can be pretty big (16KiB) and inline a lot of data; but inline extended attributes for Btrfs IIRC are limited to around 3900B on systems with 4KiB pages. Any other considerations?