What is the state of KSM/THP? Did you try disabling them ? I've seen these
can cause high iowait (although that was a virtual environment). It would be
interesting to see vmstat output.
tail /sys/kernel/mm/ksm/run /sys/kernel/mm/transparent_hugepage/khugepaged/defrag
/sys/kernel/mm/transparent_hugepage/enabled/sys/kernel/mm/transparent_hugepage/defrag
https://www.postgresql.org/message-id/20170718180152.GE17566%40telsasoft.com
I realize the postgres params don't seem related to the difference between
local/remote/NFS, but did you see all these ?
https://www.postgresql.org/docs/current/populate.html
Justin
