If I configure the swappiness value to another, from ex.: 60 to 0, then I always need to reboot the machine to the changes to take effect? Even when modifying with:
sysctl -w vm.swappiness=0
Everything is well explained in the Wikipedia page you gave.
At this point, the system will manage the swap like you just configured it, BUT if you reboot NOW, your change will be forgotten and the system will work with the default value (assuming 60, meaning than it will start to swap at 40% occupation of RAM).
You have to add the line below in
Hope it’s more clear for you now!
The opposite, in fact -- rebooting will reset the swappiness to its default value. To make it persist across reboots, you need to include a directive in a boot script or use the method recommended in the wikipedia article by adding: