What were your mdadm parameters? You spent some time tweaking ZFS, but no time tweaking mdadm? mdadm out of the box does not have very convincing performance, as we ...
A mirror only lets you use one disk in a stack in usable space (50%, or less if for some reason you want a double redundant mirror, i.e. three disks). A RAID-Z ...
Grow big or go home.
TrueNAS demands more, but delivers unmatched value ...