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.