Why is swap being used when vm.swappiness is 0?

Question

To try and fix an issue, I set swappiness to as low as possible, a 0, and swap is still being used. Why?

Running free -m gives:

total        used        free      shared  buff/cache   available
Mem:            484         241           8          58         235         134
Swap:          1023          97         926

Maybe because RAM is full? Or you had set it incorrectly? Add more detail like how exactly you configured it and the output of free -m — Byte Commander, Oct 25 '17 at 12:54
You've got a pretty small amount of memory for Ubuntu in this machine - what version of Ubuntu are you running? — Charles Green, Oct 25 '17 at 12:59
It's a VPS on Ubuntu 16.04(I can't afford a better server now) — user8292439, Oct 25 '17 at 12:59

score 5 · Accepted Answer · answered Oct 25 '17 at 13:05

5

Swappiness defines when swap is used.

For instance, swappiness of 40 defines to begin using swap when there is 40% of RAM left to use.

Swappiness of 0 defines swap is used when the RAM is full and 0% left to use.

To disable swap (totally not recommended as you could possibly end up with an unusable system), you run:

sudo swapoff -a

answered Oct 25 '17 at 13:05

mondjunge

3,296

1

Related: https://askubuntu.com/q/103915/367990 – Byte Commander Oct 25 '17 at 13:49
3

swappiness is a bit more complex than what memory usage swap begins to be used at. – Chai T. Rex Feb 28 '18 at 10:42

Why is swap being used when vm.swappiness is 0?

1 Answers1