I wouldn't worry about the system using swap while there is plenty of free RAM available. As others have stated, it is a rather common situation. The kernel might decide on moving some seldom accessed memory pages to swap in order to make RAM available for future demand. But when RAM starts running low, do keep and eye on how many bytes are actually being swapped. You can use vmstat to show the amount of bytes being swapped in/out of the system.
I.e: vmstat output of a system with no swapping taking place and marginal swap usage:
Any value > 0 means the system is actually reading from or writing to swap, at the same time you should notice a severe downgrade of the system's performance.
On Tue, May 10, 2016 at 5:23 PM, Campbell, Lance <lance@illinois.edu> wrote:
PostgreSQL 9.5.2
Linux Red Hat
I have 10 G of memory. Nagios is saying I have 2 G used and 8 G free.
Yet my swap is at 1 G.
1)Why is that?
2)Over that past week it has climbed from almost nothing to 1 G. It is a steady climb. No big jump.
