Hard disk access time, according to size

[Alexey]

Perhaps you would need to migrate from BTRFS ASAP:

Post pictures of your storagenode rig(s)

ext4 is consistently faster for storage node uses than btrfs, even when you strip btrfs from all the features that make it better than ext4. I’ve run tests in which I replayed the exact I/O performed by a node. btrfs took twice as much time to run it and was 3-4 times slower at performing the file walker process. btrfs for storage nodes sound like a good choice if you want your drives to die faster. No idea about zfs though, I haven’t measured it.