ZFS Linux: How to set options: sysctl or zfs set?

Question

linux

Ubuntu 16.04LTS.
Since the memory on the home server is very small (4 GB) (expansion is expected in the future), I decided to change a couple of parameters:

echo 536870912 > /sys/module/zfs/parameters/zfs_arc_max

and

echo 1 > /sys/module/zfs/parameters/zfs_prefetch_disable

But here's how to use when loading? Crutch in /etc/rc.local?
through sysctl it is not possible to set on / sys, he only wants / proc.
And if you turn off the prefetch "later", then it will already load the trash into memory, but does not want to unload it.
through zfs set and zpool set did not find the necessary options.

Answer 1

1) create the file /etc/modprobe.d/zfs.conf, write to it:
2) update initrd: update-initramfs -u
Done!