My hardware status has made quite a shift in the past year. Once upon a time I had beefy enough hardware and a minimal enough system that I was actually searching for ways to use more RAM. In such a case I would want a swappiness value of 0 (which is the minimum).
Fast forward to now, where I have very modest netbook and I need to make the most of swap space as to keep RAM available for what really needs it. For this, I want a higher swappiness (100 is the maximum value).
The default vaule is 60, which you can check with:
$ cat /proc/sys/vm/swappiness ----- 60
Changing the value of that file won’t do any good since it is populated at boot. So, to set things persistently we need to make a system call.
# nano /etc/sysctl.d/99-sysctl.conf ----- # set swappiness (0 - 100) # low = LESS swap use # high = MORE swap use vm.sappiness=100 # default 60
To summarize, you want a low swappiness level if you have a ton of RAM to use and want maximum performance. Conversely, if you need to use RAM sparingly, you want a high level of swappiness.