For anyone who cares... I've re-formatted the cache pool from encrypted-btrfs to just plain btrfs and the writes have droppped by almost 10x. Disk IO for [loop2] has gone from several GB's in a few minutes to maybe a 1GB in a couple of hours using iotop -a. Total writes for the SSD using LBA has gone to 1GB/hour, that is with appdata also on the same device. This will give a lifespan closer to 10 years instead of 1 year 🙂.   Anyone real smart in here, that can explain the behaviour? I
    • Thanks