Hack 89. Free command examples

by Ramesh

Free command displays all the necessary information about system physical (RAM) and swap memory.

  1. Syntax: free [options]

What is the total RAM on my system?

In the example below, the total physical memory on this system is 1GB. The values displayed below are in KB.

  1. # free
  2.        total   used    free   shared  buffers  cached
  3. Mem: 1034624   1006696 27928  0       174136   615892
  4. -/+ buffers/cache:     216668      817956
  5. Swap:    2031608       0    2031608

What is the total memory on my system including RAM and Swap?

In the following command:

  • option m displays the values in MB
  • option t displays the “Total” line, which is sum of physical and swap memory values
  • option o is to hide the buffers/cache line from the above example.
  1. # free –mto
  2.                   total       used      free     shared    buffers     cached
  3. Mem:          1010        983         27              0         170           601
  4. Swap:          1983            0    1983
  5. Total:          2994        983     2011