I have a VPS running a few websites for clients. Running
free -h shows the following:
~$ free -h total used free shared buffers cached Mem: 994M 855M 138M 39M 72M 420M -/+ buffers/cache: 362M 631M Swap: 511M 0B 511M
So I have about 138MB of free memory. My question is, how do you know when it's necessary to increase the amount of physical memory on a server? When it starts dipping into swap on a consistent basis?
At any given time I have about 140-145MB free. Does this indicate a healthy amount of free-vs-total available memory?