free

•   free command examples
  

This command is used to display the free, used, swap memory available in the system.

Typical free command output. The output is displayed in bytes.

$ free

             total       used       free     shared    buffers     cached

Mem:       3566408    1580220    1986188          0     203988     902960

-/+ buffers/cache:     473272    3093136

Swap:      4000176          0    4000176

If you want to quickly check how many GB of RAM your system has use the -g option. -b option displays in bytes, -k in kilo bytes, -m in mega bytes.

$ free -g

             total       used       free     shared    buffers     cached

Mem:             3          1          1          0          0          0

-/+ buffers/cache:          0          2

Swap:            3          0          3

If you want to see a total memory ( including the swap), use the -t switch, which will display a total line as shown below.

linuxcare@rax-laptop:~$ free -t

             total       used       free     shared    buffers     cached

Mem:       3566408    1592148    1974260          0     204260     912556

-/+ buffers/cache:     475332    3091076

Swap:      4000176          0    4000176

Total:     7566584    1592148    5974436