This is a follow-up of my previous post where i observed that enumerating the files on a unraid share with a million files took 10x the time it took vs the same stuff shared via truenas.
I now removed all the drives in the array (new feature of unraid 7) and exclusively have a btrfs "cache" of the same size. It is less "efficient": unraid xfs array with 8x 4tb drives gave 24tb usable space with 2 drives redundancy. Now with btrfs i have 16tb usable space with only 1 drive redundancy. But the SPEED difference is insane.
Before, syncing a 1tb directory using unison, and the contents were already present on both servers: 3 hours
Now: 30 seconds