arc

printf 'options zfs zfs_arc_max=2147483648' >> /etc/modprobe.d/zfs.conf
echo 3 > /proc/sys/vm/drop_caches

e para verificar:
cat /proc/spl/kstat/zfs/arcstats |grep c_

https://serverfault.com/questions/581669/why-isnt-the-arc-max-setting-h…