====== Linux Guests ======

Linux Guest on BTRFS:
  * BTRFS with single copy of meta, system and data
  * I/O is better on modern guest Kernel 6.1 (vs 5.10)
  * I/O is better whem VM storage is "no cache"
    * sync writes goes to ZFS ZIL
    * With "Writeback" cache - ZFS ZIL was not utilized so high like with "no cache"