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”