Most of us don’t often think about swap space unless we run into a problem on our systems that suggests we don’t have enough. Even so, viewing and gauging the adequacy of swap space on a system is not overly complicated, and knowing what’s normal for your system can help you spot when something is wrong. So let’s check out some commands that can help you look into your swap space. But first, let’s review some fundamentals.
What swap space is and how it’s used
Swap space is disk space that acts something like an extension of memory. It gets used when the system’s physical memory (RAM) is full and the system needs more memory resources. It’s called “swap” because the system will move some inactive pages in memory into the swap space so that it can accommodate more data in RAM. In other words, it provides a way to free up RAM on a busy system.
Source:: Network World – Linux