Я дошёл до этапа подключения по сетке.
ZFS:
zpool create -o ashift=12 -O compression=lz4 -O atime=off -O recordsize=64k nvme /dev/nvme0n1 /dev/nvme1n1 /dev/nvme3n1 -f
zfs create -s -V 2.7T -o volblocksize=64k -o compression=lz4 nvme/iser
fio -name=rndw4k16 -ioengine=libaio -direct=1 -buffered=0 -invalidate=1 --runtime=100 --time_based=1 -numjobs=4 -bs=64k -iodepth=32 -rw=randwrite -filename=/dev/mapper/mpat
WRITE: bw=916MiB/s (960MB/s), 229MiB/s-229MiB/s (240MB/s-240MB/s), io=54.1GiB (58.0GB), run=60460-60460msec

mdadm:
fio -name=rndw4k16 -ioengine=libaio -direct=1 -buffered=0 -invalidate=1 --runtime=100 --time_based=1 -numjobs=1 -bs=64k -iodepth=32 -rw=randwrite -filename=/dev/mapper/mpathd
WRITE: bw=1748MiB/s (1833MB/s), 1748MiB/s-1748MiB/s (1833MB/s-1833MB/s), io=121GiB (130GB), run=71062-71062msec