Memory usage

The following command can be used to show your current memory usage:

  free -m

This will return output similar to the following:

  # free -m
  total       used       free     shared    buffers     cached
  Mem:          7872       2238       5634          0        183       1702
  -/+ buffers/cache:        351       7520
  Swap:            0          0          0

At first glance, it may seem that the server only has 5.3G available, but the value we're interested in is the one just below it, in the -/+ buffers/cache section. This takes Linux's native disk caching into account, which can otherwise makes it look as though most of your RAM is being used up.

For further explanation, see: http://www.linuxatemyram.com/