Hello,
This is RHEL 5.7. swap is almost full, but I am not sure, what to release and how to release space. This is production server so I would like to try all possible options before reboot.
Check vmstat looking at PI column if actual swapping is occurring at a certain moment.
If not, you are fine at this moment (probably not due to free memory available on the machine from your post)
What should worry you that sometime in past swapping occurred and was used by a process(es) which is no longer running.
You might want to consider putting vmstat in cron to monitor your machine to pinpoint the time when swapping occurs, then identify what is being ran to cause such high memory usage.
As of now, current issue is, we are installing a software which requires 1 GB of free swap space. Due to less space, that is failing. I was checking if I can make it work without adding more swap space. Here is vmstat output. Does it point to something ?
Are you running oracle? The SGA is created then swap of the same size is allocated. There is never any swapping activity once the SGA's are created. To allow other processes and oracle to get what they need, we created 500GB of swap - on a machine with 256 GB memory. Many applications do this. The only workaround is to add swap because of badly behaved processes. In this particular scenario.