High Memory Usage on Linux Server

Solution 1:

-/+ buffers/cache: 1

You're using only 1 GB. The rest is system cache.

Solution 2:

This is perfectly normal. If you want memory not to be used, take it out of the server and put it on your desk. Free memory is wasted memory.

Linux, like most modern operating systems, can directly transition memory from one use to another. Making it free in the middle has costs associated with it and no benefits associated with it. So sensible operating systems don't do it unless they have to.

Free memory is only needed for certain very specific cases. For example, free memory is needed to hold data received over the network temporarily until the OS can process it. Because free memory has a high cost associated with it (it's as if that memory wasn't there as far as performance goes) the system only keeps as much memory free as it needs for these special situations.

Solution 3:

Read on this: Linux Ate My RAM