Kernel runtime parameters

sysctl -a

sudo sysctl -a

See one parameter

sudo sysctl <parameter>

Write parameter for this session:

sudo sysctl -w <parameter>=<value>

See all *.conf

ls -a /etc/sysctl.d/

Add persistent changes

Create new *.conf file

sudo nano /etc/sysctl.d/swap-less.conf 

and add the desired change

vm.swapiness=20

In order to apply those changes right away, and not wait for the next reboot,

sudo sysctl -p /etc/sysctl.d/swap-less.conf

suso nano /etc/sysctl.conf