Definition of terms found in the graph legend
- swap.out (int, bytes): data swapped out since last boot calculated from page number
- total (int, bytes): total swap memory
- free (int, bytes): free swap memory
- used (int, bytes): used swap memory
- swap.in (int, bytes): data swapped in since last boot calculated from page number
What to look for? Here a scenario ...
In these two images showing swap.out:
We are seeing more swap activity than we would like.
We might ask, "Is swappiness on this server set correctly?"
If it is the default setting, even with a large amount of real memory the system will still move things to swap. Setting swappiness to 1 should reduce/eliminate it.