I&#x27;m going to disagree with you re: compression.  Compression at the FS layer brings a lot of benefits, and generally most workloads are IO constrained not CPU constrained.  Compression at the FS improves IO at the expense of CPU.<p>Hadoop is a completely different workload, and maybe not something for ZFS or btrfs.  Our Hadoop nodes are not raid, just JBOD ext4 disks.  We have been conidering btrfs with nodatacow mount option and lz4 compression, however.  We haven&#x27;t decided if it&#x27;s better to compress within Hadoop or at the fs layer yet.  I would be curious on your findings.