Encountering WD SMR mess in real life with TrueNAS/FreeNAS

Note: FreeNAS recently rebranded as TrueNAS. Since I still haven’t upgraded my system I’ll be referring to it as FreeNAS in this post. Earlier this year, I tangentially followed the story on Western Digital shipping SMR (shingled magnetic recording) drives labelled as “Red” NAS drives. While these drives do provide satisfactory performance for non NAS use, they are significantly slower for most NAS’s, and virtually unusable for ZFS, used in