I noticed that the memory usage was too high on one of my servers, and as always, the candle was burning from both sides.
I checked the ARC Size, and it was too high
# kstat -p zfs:0:arcstats:size zfs:0:arcstats:size 15032385536
So I decided to set the ZFS ARC Max, which was new to me, but after going over the docs, all I needed to do was
# echo 'set zfs:zfs_arc_max = 4294967296' >> /etc/system
and then finally reboot
# shutdown -g0 -y -i 6
That’s pretty much it.